VOL.  XXXII 

no.  3 


PSYCHOLOGICAL  REVIEW  PUBLICATIONS 


WHOLE  NO.  H5 
1923 


Psychological  Monographs 

EDITED  BY 

JAMES  ROWLAND  ANGELL,  Yale  University 
HOWARD  C.  WARREN,  Princeton  University  ( Review ) 

JOHN  B.  WATSON,  New  York  (J.  of  Exp.  Psychol .) 

SHEPHERD  I.  FRANZ,  Govt.  Hosp.  for  Insane  {Bulletin)  and 
MADISON  BENTLEY,  University  of  Illinois  {Index) 


STUDIES  FROM  THE  PSYCHOLOGICAL 
LABORATORY  OF  OBERLIN  COLLEGE 


EDITED  BY 

RAYMOND  HERBERT  STETSON 

Professor  of  Psychology 


PSYCHOLOGICAL  REVIEW  COMPANY 
PRINCETON,  N.  J. 


Agents:  G.  E.  STECHERT  &  CO.,  London  (2  Star  Yard,  Carey  St.,  W.  C.) 

Paris  (16,  rue  de  Conde) 


Digitized  by  the  Internet  Archive 
in  2019  with  funding  from 
Princeton  Theological  Seminary  Library 


https://archive.org/details/studiesfrompsychOOstet 


TABLE  OF  CONTENTS 


I.  The  Hair  Follicle  and  the  Sense  of  Pressure. 

By  R.  H.  Stetson 

II.  Mechanism  of  the  Different  Types  of  Movement. 

By  R.  H.  Stetson,  with  a  preliminary  report  of 
experimental  data  by  J.  A.  McDill 

III.  Measurements  of  Rhythmic  Unit-Groups  at  Different 

Tempos.  By  R.  H.  Stetson  and  T.  E.  Tuthill 

IV.  The  Application  of  the  Binet-Simon  Tests  to  Groups 

of  White  and  Colored  School  Children. 

By  G.  R.  Wells 


PAGE 

I 

18 

4i 


52 


THE  HAIR  FOLLICLE  AND  THE  SENSE  OF 

PRESSURE 

BY 

R.  H.  Stetson 

It  has  been  assumed  that  the  end-organs  for  pressure  are  lo¬ 
cated  at  separate  points,  like  those  of  warmth  and  cold.  Careful 
exploration  of  the  skin  by  Goldscheider  and  v.  Frey1  revealed 
separate  spots  where  the  sense  of  pressure  reaches  a  maximum. 
The  intervening  skin  is  also  sensitive  to  pressure,  but  that  may 
be  the  result  of  the  transmission  of  the  stimulus  through  yielding 
skin  structures  to  the  nearest  ‘pressure  spots.’  The  actual  end- 
organs  for  warm  and  cold  are  in  doubt,  but  it  has  seemed  easy  to 
determine  the  end-organs  for  pressure.  On  hairy  areas  maximum 
sensitiveness  to  pressure  occurs  at  a  spot  to  the  ‘windward’  of 
the  hair,  and  is  evidently  due  to  the  stimulation  of  the  hair  follicle. 
The  follicle  lies  embedded  in  the  skin  at  an  angle  so  that  the 
‘pressure  spot’  occurs  over  the  follicle  a  millimeter  or  so  from 
the  point  where  the  hair  emerges.  It  is  easy  to  see  the  relation, 
for  stimulation  of  the  ‘pressure  spot’  moves  the  hair  shaft. 

The  histology  of  the  hair  follicle  reveals  an  elaborate  innerva¬ 
tion  which  might  well  mediate  an  important  cutaneous  quality. 
A  double  innervation  has  been  described  and  is  a  commonplace 
in  the  text  books.2  A  detailed  account  of  the  innervations  of  the 
follicle  with  references  to  the  original  studies  and  with  drawings 
of  the  structures  is  given  by  Prenant  and  Bouin.3  They  speak 
of  the  neural  ring  of  non-medullated  fibres  which  originate  from 
a  nerve  entering  the  follicle  at  the  level  of  the  opening  of  the 

1  A.  Goldscheider,  Ges.  Abhandl.  I,  1898.  v.  Frey,  Vorles.  u.  Physiol.  1894. 
v.  Frey,  Ergebnisse  d.  Physiol.  (Asher  u.  Spiro)  1913-  Bd.  13,  S.  96.  Physiol, 
d.  Sinnesorgane  d.  mench.  Haut.  II,  Der  Drucksinn. 

2  Stewart,  Manual  of  Physiol.,  1910;  Howell,  Physiol.,  1896,  p.  260;  Bailey, 
Histol.,  1910,  p.  365;  Ferguson,  Hor.  Histol.,  1905,  p.  225;  Piersol,  Nor.  Histol., 
1910,  p.  328. 

3  Prenant  et  Bouin,  Traite  d’Histologie,  1911,  p.  624  ff. 


2 


R.  H.  STETSON 


sebaceous  glands.  This  neural  ring  is  double  and  lies  well  out¬ 
side  the  vitreous  membrane.  On  the  outside  surface  of  the 
vitreous  membrane  at  the  level  of  the  neural  ring  and  extending 
below  it  are  a  number  of  enlarged,  spatulate  endings,  possibly  de¬ 
rived  from  the  fibrils  of  the  ring.  There  is  also  an  innervation 
of  the  root  proper  of  the  hair,  nerve  fibres  which  enter  the 
papilla  of  the  follicle  at  the  lower  end  of  the  follicle.  Szymono- 
wicz4  has  made  a  detailed  study  of  the  innervation  of  the  human 
hair  by  the  methylen  blue  method,  and  has  been  able  to  reconcile 
the  statements  of  previous  authors.  He  speaks  of  the  neural  ring 
and  the  flattened  endings  on  the  outside  of  the  vitreous  membrane 
just  below  the  sebaceous  glands,  and  of  the  nerve  entering  the 
papilla  of  the  hair.  His  detailed  drawings  give  an  idea  of  the 
form  of  the  nerve  endings  and  of  their  distribution.  The  ma¬ 
terial  used  was  freshly  excised  from  the  eyelid  and  from  the 
lower  lip.  The  studies  of  the  human  hair  follicle  have  been  con¬ 
fined  to  a  few  localities  on  the  human  body. 

The  tactile  hairs  of  many  mammals  are  undoubtedly  important 
touch  organs,  and  have  been  studied.  Their  innervation  is  not 
unlike  that  of  the  human  hair;  this  increases  the  probability  that 
the  human  hair  is  an  important  tactile  organ.5 

Actual  experiment  shows  that  the  hair  itself  is  an  important 
factor  in  the  pressure  sense.  Vincent  quotes  Sherrington :  “On 
9  sq.  cm.  of  skin  from  which  the  hairs  have  been  shaved,  the 
liminal  stimulus  was  found  to  be  36  mgm,  whereas,  on  the  same 
surface  before  it  was  shaved,  2  mgm  was  the  liminal  stimulus.” 
And  it  is  well  known  that  the  hair  itself  is  more  sensitive  to  pres¬ 
sure  than  the  ‘pressure  spot1  near  the  hair. 

Following  v.  Frey,  Thumberg6  and  others  speak  of  the  hair 
acting  “as  a  lever,  in  that  the  neural  stimulation  may  be  described 
as  a  moment  of  rotation  wherein  the  surface  of  the  skin  acts  as 

4  L.  Szymonowicz,  Ub.  die  Nervenendigungen  in  d.  Haaren  d.  Menchen, 
Archiv.  f.  mikro.  Anat.  1909,  Bd.  74,  S.  622-634. 

5  S.  B.  Vincent,  The  tactile  hairs  cf  the  white  rat,  J.  Comp.  Neurol,  v.  23, 
!9I3>  P-  1-38.  J.  E.  Eckert,  The  innervation  of  the  integument  of  Chiroptera, 
J.  of  Morphol.,  1914,  v.  25,  p.  315-320. 

6  Nagel’s  Handb.  Ill,  1905,  S.  664. 


THE  HAIR  FOLLICLE 


3 


a  fulcrum.”  This  notion  of  the  hair  as  a  lever  of  the  first  class 
in  which  the  epidermis  at  the  point  of  emergence  acts  as  a  fulcrum 
so  that  the  movement  is  transmitted  to  the  follicle  has  been  com¬ 
monly  accepted.  It  is  apparent  that  the  skin  does  act  as  a  ful¬ 
crum  for  the  tactile  hairs  of  animals  when  they  are  moved,  and 
something  like  that  must  take  place  when  the  human  hair  is 
erected  by  the  muscles  of  the  hair  follicles.  Nevertheless  the  ob¬ 
servation  is  inaccurate  when  applied  to  the  human  hair  as  a  tactile 
organ. 

Despite  this  general  acceptance  of  the  hair  follicle  as  the  pres¬ 
sure  organ  in  hairy  areas,  there  are  certain  acts  not  in  accord. 
It  is  hard  to  understand  why  the  scalp  and  the  bearded  area  of 
the  face  should  not  be  far  more  sensitive,  if  they  are  crowded 
with  pressure  organs.  Moreover  the  ‘pressure  spots’  unlike  the 
warm  and  cold  spots,  are  but  points  of  maximum  sensitiveness, 
and  the  skin  is  everywhere  sensitive  to  pressure.  Murray7  speaks 
of  the  difficulty  of  a  precise  localization  of  the  ‘pressure  spots,’ 
and  of  the  apparent  existence  in  the  intermediate  areas  of  other 
spots  of  approximately  equal  sensitiveness,  and  of  the  impos¬ 
sibility  of  reproducing  the  granular  sensation  by  electrical  stimu¬ 
lation  of  the  verified  spots.  The  extreme  delicacy  of  the  response 
when  the  skin  is  lightly  touched  with  cotton,  etc.  makes  it  doubt¬ 
ful  if  there  is  transmission  to  such  deep-lying  structures  as  the 
follicles.  Merkel8  hazarded  the  guess  that  certain  simple  end- 
organs  scattered  in  the  skin  as  well  as  about  the  hair  follicles  were 
“touch  corpuscles.”  And  certainly  Murray’s  statement:  “The 
greater  efficiency  of  pressure  over  the  hair  bulb  in  the  production 
of  the  pressure  sensation  is  probably  due  to  the  mechanical  effect 
through  the  grinding  down  of  the  comparatively  solid  follicle 
upon  the  underlying  endings”  is  worth  noting.  There  is  good 
reason  to  consider  his  assertion  that  “the  so-called  granular  pres¬ 
sure  is  not  in  itself  an  element  but  is  a  complex  of  deeper  pressure 
with  contact.  .  .  .  ”9 

7  E.  Murray,  Qual.  Anal,  of  Tickle,  Am.  J.  Psy.  1908,  v.  19  (3),  p.  299. 

8  F.  R.  Merkel,  Tastzellen  in  Tastkorperchen  bei  d.  Hausthieren  u.  b.  Men- 
chen,  Archiv  f.  mikro  Anat.  1876,  Bd.  11,  S.  647. 

9  Murray,  ibid. 


4 


R.  H.  STETSON 


PROBLEM 

It  is  possible  to  investigate  the  function  of  the  hair  follicle  as 
an  end-organ  for  the  sense  of  pressure  by  two  methods : 

1)  The  neural  endings  of  the  follicle  may  be  removed,  and  the 
effect  on  the  sensitiveness  of  the  hair  itself  and  of  the  adjacent 
areas  studied; 

2)  The  pressure  sensitivity  of  areas  denuded  of  follicles  may 
be  investigated. 

Before  operating  the  hair  follicle,  preliminary  studies  of  the 
movements  of  the  follicle  and  the  resulting  sensations  were  made. 
The  skin,  carefully  scrubbed  and  softened,  was  moistened  with  a 
little  water  and  glycerin,  and  examined  with  a  Zeiss  binocular 
erecting  microscope  magnifying  c.9  times.  A  strong  red  light 
was  used  for  illuminating;  unlike  the  white  light  the  red  light 
is  not  reflected,  rendering  the  surface  opaque,  and  it  penetrates 
the  skin  to  a  slight  depth.  By  this  means  the  hair-shaft  of  a  dark¬ 
haired  subject  may  be  traced  about  two  millimeters  into  the  skin, 
and  the  movement  of  the  follicle  noted  when  stimulation  is  ap¬ 
plied. 

On  moving  the  hair  on  back  of  hand  or  on  forearm,  under 
such  conditions,  it  is  easy  to  see  that  the  description  of  the  hair 
as  a  lever  of  the  first  class  is  inaccurate.  The  lower  end  of  the 
follicle  is  far  more  firmly  fixed  than  the  surface  where  the  hair 
emerges,  and  the  movement  affects  the  lower  end  little  if  at  all, 
while  the  upper  part  of  the  follicle  and  the  skin  at  the  point  of 
emergence  undergo  considerable  deformation.  The  hair  is  a 
lever  of  the  second  class,  with  the  fulcrum  at  the  lower  end  of 
the  follicle,  rather  than  a  lever  of  the  first  class  with  the  fulcrum 
at  the  surface  where  the  hair  emerges.  The  hair  is  like  a  willow 
shoot  deeply  rooted  in  light  sand;  when  the  shoot  is  moved,  the 
part  just  below  the  surface,  and  the  surface  layer  of  the  sand 
itself  are  stirred,  but  the  root  of  the  willow  shoot  is  not  moved. 

For  a  careful  study  of  the  movements  of  the  follicle  including 
the  papilla,  the  hairs  of  the  scrotum  were  used;  the  skin  is  thin 
and  transparent,  the  follicles  large  and  single,  and  the  papilla 
clearly  defined  by  a  pigmented  spot.  On  the  scrotum  as  else- 


THE  HAIR  FOLLICLE 


5 


where,  the  movement  of  the  skin  about  the  point  where  the  hair 
emerges  is  a  most  striking  item  in  the  stimulation  of  the  hair. 
The  skin  may  be  fixed  with  collodion,  and  the  lower  end  of  the 
follicle  moved  two  millimeters  without  causing  sensation.  This 
was  verified  by  repeated  observations  on  several  hairs  on  each 
of  three  subjects,  two  of  whom  were  trained  observers. 

When  traction  is  exerted  on  the  hair  it  is  easy  to  see  that  the 
lower  part  of  the  follicle  is  not  the  significant  point;  the  end  of 
the  follicle  may  be  moved  back  and  forth  two  or  three  millimeters 
without  the  sensation  of  pulling  being  noted.  On  the  other  hand, 
if  the  skin  is  fixated  by  putting  a  blunt  point,  or  a  hook  partly 
encircling  the  hair,  into  the  pit  of  the  hair,  a  slight  traction  is 
quickly  perceived;  much  greater  traction  must  be  exerted  if  the 
skin  is  not  fixated.  This  indicates  that  the  pressure  sensations 
are  mediated  by  the  upper  part  of  the  follicle,  and  possibly  by 
the  skin  surface  at  the  point  of  emergence.  These  observations 
were  verified  on  several  hairs  on  each  of  five  subjects,  two  of 
whom  were  trained  observers. 

OPERATION  ON  THE  HAIR  FOLLICLE 

Removal  of  the  lower  part  of  the  Follicle.10 

The  area  selected  for  the  operation  was  the  anterior  portion  of 
the  scrotum  near  the  median  line.  The  surface  is  fairly  sensitive 
to  pressure,  and  the  localization  is  about  as  good  as  on  the  fore¬ 
arm.  The  follicles  are  easily  seen  and  operated.  They  are  single 
and  widely  separated,  as  in  no  other  part  of  the  body.  A  strong 
red  light  was  used,  and  the  work  was  done  under  the  binocular 
with  a  magnification  of  c.  9  times.  To  fixate  the  follicle,  a  No. 
14  or  16  needle  (f.n.  in  Fig.  1)  in  which  a  minute  bend  had  been 
made  was  passed  through  the  skin,  under  the  follicle  at  right 
angles,  and  out  on  the  other  side,  pinning  the  follicle  in  a  tiny 
stitch  in  the  skin  (Figs.  1  and  2).  The  follicle  lay  in  the  bend 
of  the  needle  (Fig.  2).  Without  local  anesthesia,  a  transverse  in- 

10  Mr.  C.  C.  W.  Nicol,  Assistant  in  the  Oberlin  Laboratory  1912-13,  assisted 
in  the  development  of  a  rather  difficult  and  exacting  technic,  and  did  a  part 
of  the  tedious  work  of  operating  and  testing  the  hair  follicles. 


6 


R.  H.  STETSON 


Tfg.l 


cision  was  made  just  over  the  needle  (i  in  Figs,  i  and  3)  with 
a  small  scalpel  ground  out  of  a  needle;  then  the  papilla  (c,  in 
Fig.  3)  with  about  half  a  millimeter  of  the  follicle  was  snipped 
off  (at  d  in  Fig.  3)  with  scissors  ground  to  fine  slim  points.  The 
severed  portion  was  removed  with  fine  tweezers.  It  is  unneces¬ 
sary  to  snip  off  the  lower  part  of  the  follicle;  dissecting  it  loose 
breaks  all  connections;  but  for  the  sake  of  certainty  the  lower  part 
of  the  follicle  was  always  removed.  The  operations  were  done 
with  the  usual  precautions,  without  local  anesthesia.  The  tissues 
are  resistent  to  infection  and  the  wounds  heal  very  rapidly.  There 


THE  HAIR  FOLLICLE 


7 


cross-section  at  b' 


8 


K.  H.  STETSON 


was  a  slight  induration  about  the  scar,  but  the  reaction  had  dis¬ 
appeared,  and  the  wounds  were  practically  healed  in  two  days. 

Lower  part  of  the  follicle  removed,  on  scrotum :  when  tested  the 
stimulus  was  applied  to  the  hair. 


St.  3  follicles  operated,  tested  48  hrs.  later 


2 

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48 

In  every  case  every  hair  was  sensitive  after  the  operation,  and 
there  was  no  difference  in  quality  or  localization  whereby  the 
operated  hairs  could  be  distinguished  from  the  neighboring  nor¬ 
mal  hairs  by  any  of  the  subjects,  two  of  whom  were  trained  ob¬ 
servers.  Care  was  taken,  of  course,  in  applying  the  stimulus  to 
the  hair  shaft,  not  to  touch  the  skin  or  other  hairs;  if  necessary 
the  microscope  was  used  in  stimulating  and  observing  the  hairs. 

When  tested  with  the  v.  Frey  esthesiometer,  in  all  cases  the 
skin  about  the  point  of  emergence  and  between  the  operated  hairs 
was  as  sensitive  as  the  neighboring  normal  areas.  The  sensitive¬ 
ness  was  somewhat  reduced  on  the  ‘pressure  spots’  as  they  were 
near  slightly  indurated  scars.  (E.g.  readings  for  normal  ‘pres¬ 
sure  spots’  14-15,  for  intermediate  areas  16-18,  for  indurated 
scars  20-23.) 

The  v.Frey  esthesiometer  used  throughout  the  tests  was  fur¬ 
nished  with  a  ‘hair’  made  by  reducing  a  steel  hair-spring  in  a  bath 
of  dilute  nitric  acid.  A  tip  was  made  by  inserting  the  hair-spring 
in  flame  and  producing  a  globule  of  oxid,  or  by  attaching  a  globule 
of  hard  cement;  the  oxid  or  cement  is  ground  down  on  a  fine 
carborundum  hone  to  the  proper  dimensions.  Such  a  ‘hair’  does 
not  lose  its  elasticity,  is  very  uniform  throughout  its  length,  and 
is  not  affected  by  moisture. 

As  to  the  precise  sensitiveness  of  the  operated  hairs,  it  was  the 


THE  HAIR  FOLLICLE 


9 


judgment  of  both  experimenters  that  the  operated  hairs  were 
slightly  less  sensitive  than  the  normal  hairs;  the  subjects  could 
make  no  such  discrimination.  It  is  of  course  difficult  to  get  any 
quantitative  tests  for  stimulation  of  a  hair,  and  nothing  could 
be  based  on  this  judgment.  A  slight  reduction  of  sensitiveness 
might  well  be  expected  from  the  disturbance  and  from  the  slight 
induration  which  limited  the  movement  of  the  follicle  and  of  the 
skin. 

Whether  the  papilla  is  removed,  or  merely  dissected  loose,  the 
hair  falls  out  in  a  week  or  so;  but  it  remains  in  place  long  enough 
for  tests.  The  time  (two  days)  between  operation  and  test  is 
of  course  much  too  short  for  any  regeneration  of  the  nerve 
fibrils. 

Removal  of  the  Upper  Part  of  the  Follicle 

It  is  agreed  that  the  nerve  supplying  the  elaborate  innervation 
of  the  upper  part  of  the  follicle  enters  at  the  level  of  the  opening 
of  the  sebaceous  glands,  and  that  the  neural  ring  and  the  flattened 
endings  are  just  below  the  glands.  The  sebaceous  glands  are 
easily  seen  on  the  scrotum.  It  is  possible  to  remove  the  upper 
part  of  the  follicle  so  as  certainly  to  eliminate  the  upper  innerva¬ 
tion  of  the  follicle. 

The  follicle  was  fixated  by  pinning  it  transversely  into  a  tiny 
stitch  in  the  skin  (Fig.  i )  ;  the  follicle  lies  in  a  minute  bend  of  the 
needle  (Fig.  2).  A  transverse  incision  (i,  Fig.  1  and  3)  is  made 
in  the  skin  just  above  the  needle.  The  upper  part  of  the  follicle 
is  carefully  dissected  from  the  skin  by  inserting  beneath  the  skin 
a  spade-shaped  blade  with  rounded  end ;  then  with  a  hook-shaped 
blade  sharp  on  both  inner  and  outer  curves,  the  upper  part  of 
the  follicle  is  freed  at  the  sides  and  beneath,  down  to  the  level 
of  the  fixating  needle  (f.  n.,  Fig.  3).  Care  is  taken  not  to  pierce 
the  skin.  With  a  pair  of  special  tweezers  the  tough,  elastic  vit¬ 
reous  membrane  is  stripped  off  the  hair,  beginning  at  the  level 
of  the  fixating  needle  (f.n.,  Fig.  3)  and  working  under  the  skin 
until  the  follicle  has  been  stripped  out  to  the  point  of  emergence. 
The  hair  shaft  is  left  in  place. 


10 


R.  H.  STETSON 


The  knives  were  ground  from  No.  5  needles.  The  tweezers 
were  made  of  two  “crow-quill”  steel  pens  carefully  ground  until 
the  points  are  very  slender.  The  four  minute  strips  of  steel  were 
then  bent  at  the  tips  until  slightly  hooked  and  ground  sharp  at 
the  squared  tips.  These  four  prongs  encircle  the  hair  and  strip 
away  the  follicle,  but  are  elastic  enough  not  to  tear  the  hair. 

In  this  fashion  the  follicle  is  cleared  away  for  about  one-half 
its  length ;  care  is  taken  not  to  disturb  the  lower  end  of  the  follicle. 
The  transverse  incision  is  1.5-3  mm.  from  the  emergence  point 
and  the  skin  about  the  hair  is  intact.  The  reaction  subsides  in  a 
day  or  so  and  the  wound  heals  in  a  very  short  time,  leaving  the 
hair  uninjured — unlike  the  first  operation. 


Removal  of  the  upper  part  of  the  follicle  on  scrotum ;  when 
tested  the  stimulus  was  applied  to  the  hair. 


St.  I 

follicles ; 

tested  after 

48  hrs. 

Sensation  nearly  normal 

I 

u 

a 

a 

48 

a 

a 

decidedly  subnormal 

Ni.  3 

u 

a 

a 

12 

a 

a 

normal;  after  48  hrs. 
normal 

St.  4 

u 

a 

a 

12 

a 

a 

normal 

P.  1 

u 

a 

a 

12 

a 

a 

normal 

M.  3 

a 

a 

a 

12 

a 

a 

normal 

1 

a 

<< 

a 

12 

a 

a 

decidedly  subnormal ;  after  48 
hrs.  c.  normal 

K.  5 

a 

a 

a 

12 

a 

a 

normal ;  after  48  hrs.  nor¬ 
mal.  Follicles  in  a  group. 

Ma.  5 

a 

a 

a 

12 

a 

a 

normal;  after  48  hrs.  nor¬ 
mal.  Follicles  in  a  group. 

M.  4 

a 

a 

a 

12 

a 

a 

normal 

St.  4 

a 

a 

a 

48 

a 

a 

normal.  These  hairs  were 
compared  with  normal 
hairs  which  had  been 
scarified  without  injuring 
the  follicle ;  no  difference 
found. 

K.  4 

a 

a 

a 

12 

a 

a 

normal;  after  4  days,  nor¬ 
mal. 

Ni.  3 

a 

a 

a 

12 

a 

a 

normal 

1 

a 

a 

a 

12 

a 

a 

slightly  subnormal 

L.  1 

a 

a 

a 

12 

a 

a 

decidedly  subnormal 

1 

a 

a 

a 

12 

a 

a 

slightly  subnormal 

Ni.  2 

a 

a 

a 

24 

a 

a 

slightly  subnormal 

K.  4 

a 

a 

a 

12 

a 

a 

subnormal;  4  days  after, 
subnormal. 

THE  HAIR  FOLLICLE 


ii 


s. 

1  “ 

it 

tt 

48 

a 

“  normal 

1  “ 

tt 

ti 

48 

u 

decidedly  abnormal ;  scar 
tissue. 

L. 

1  “ 

a 

a 

24 

tt 

“  normal 

1 

tt 

tt 

24 

n 

slightly  abnormal 

T. 

2  “ 

a 

a 

24 

a 

subnormal ;  48  hrs.  after, 

normal 

Ma. 

2  “ 

a 

u 

24 

a 

“  normal 

K. 

1  “ 

tt 

a 

24 

a 

decidedly  subnormal ;  3  days 
after,  slightly  subnormal. 

1  “ 

a 

n 

72 

n 

“  normal 

S. 

3 

tt 

a 

24 

a 

sensation  subnormal ;  48  hrs. 
after,  slightly  subnormal. 

L. 

1 

tt 

tt 

48 

tt 

“  slightly  subnormal 

Ma. 

1 

tt 

tt 

48 

a 

slightly  subnormal 

63  hairs  operated  on  eight  subjects. 

Of  these  63  follicles,  4  proved  to  be  decidedly  subnormal,  though 
not  insensitive;  it  is  possible  that  in  those  cases  the  nerves  of 
the  skin  were  severed,  or  the  formation  of  scar  tissue  involved 
the  fibers  supplying  the  skin  about  the  hair. 

From  these  results  it  is  easily  seen  that  there  is  a  tendency  to 
reduction  of  the  sensitiveness  of  the  hair  when  the  upper  innerva¬ 
tion  of  the  follicle  is  removed.  In  many  cases  this  is  not  apparent 
on  scrotal  areas  but  it  comes  out  more  plainly  on  other  parts  of 
the  body. 

The  lower  arm  has  been  much  used  for  study  of  skin  sensa¬ 
tions.  It  is  not  entirely  satisfactory  for  the  present  purpose,  be¬ 
cause  it  is  difficult  to  find  single  hairs.  On  nearly  all  parts  of  the 
body  the  hairs  are  closely  set  in  threes,  one  large  hair  with  a  small 
guard-hair  on  either  side. 

Removal  of  upper  half  of  follicle  on  lower  arm ;  when  tested 
the  stimulus  was  applied  to  the  hair. 

St.  2  follicles ;  tested  after  24  hrs.  Subnormal :  2  days  after,  subnormal. 

2  “  “  “  48  “  Subnormal 

Tu.  2  “  “  “  48  “  Subnormal 

M.  1  “  “  “  6  days  Subnormal 

Removal  of  the  upper  half  on  upper  leg,  just  above  patella; 
when  tested  the  stimulus  was  applied  to  the  hair. 

St.  2  follicles;  tested  after  24  hrs.  Subnormal;  6  days  after  nearly  normal. 

2  “  “  “  24  “  Subnormal ;  4  days  after  nearly  normal. 


12 


R.  H.  STETSON 


Removal  of  upper  half  of  follicle  on  lower  leg;  when  tested 
the  stimulus  was  applied  to  the  hair. 

L.  4  follicles;  tested  after  48  hrs.  Subnormal 

2  “  “  “  4  days  Subnormal 

M.  3  “  “  “  48  hrs.  Subnormal 

2  “  “  “  48  “  Subnormal 

The  point  of  the  hip,  just  outside  the  area  of  pubic  hair  is  a 
good  locality  for  testing  hair  follicles;  the  hairs  are  large,  sparse, 
and  single. 

Upper  half  of  the  follicle  removed  on  point  of  hip;  when  tested 
the  stimulus  was  applied  to  the  hair. 


St. 

6 

follicles : 

tested  after 

6  days, 

Subnormal 

M. 

2 

ii 

ii 

a 

4 

ii 

Subnormal 

3 

ii 

ii 

a 

2 

ii 

Nearly  normal 

Ni. 

3 

ii 

a 

a 

2 

ii 

Subnormal 

4 

a 

ii 

a 

4 

ii 

Slightly  subnormal 

L. 

2 

a 

a 

a 

4 

ii 

Subnormal 

2 

a 

a 

a 

4 

ii 

Nearly  normal 

N. 

4 

a 

a 

a 

12 

hrs. 

Subnormal 

Sh. 

5 

a 

a 

a 

1 1 

days  Subnormal 

L. 

1 

ii 

a 

a 

6 

ii 

Subnormal 

M. 

1 

a 

a 

a 

2 

ii 

Subnormal 

1 

a 

a 

a 

2 

ii 

Almost  normal 

(The  interval  between  operating  and  testing  was  lengthened  because  more 
time  was  needed  for  healing.) 

In  all  these  cases  the  removal  of  the  upper  part  of  the  follicle, 
the  quality  of  the  hair  sensation  is  not  changed;  the  subjects  are 
unable  to  discriminate  between  the  operated  hairs  and  the  neigh¬ 
boring  hairs.  It  is  evident  however  that  there  is  a  decided  re¬ 
duction  of  the  sensitiveness  of  the  hairs  operated  on  other  parts 
than  the  scrotum.  That  this  does  not  occur  more  often  on  the 
scrotum  is  probably  due  to  the  greater  size  and  rigidity  of  the 
hair,  and  the  greater  mobility  of  the  surface,  whereby  the  move¬ 
ment  of  the  hair-shaft  produces  a  decided  deformation  of  the 
skin. 

Removal  of  both  Upper  and  Lozver  Innervations  of  the  Follicle 

Although  the  preliminary  experiments,  and  the  removal  of  the 
lower  end  of  the  follicle  indicate  that  the  lower  innervation  of 


THE  HAIR  FOLLICLE 


13 


the  follicle  has  no  influence  on  the  pressure  sensation,  it  is  pos¬ 
sible  to  argue  that  the  pressure  sensation  remaining  after  the  re¬ 
moval  of  the  upper  half  of  the  follicle  is  not  due  to  the  deforma¬ 
tion  of  the  skin  about  the  hair,  but  to  the  stimulation  of  the  lower 
innervation.  To  test  this,  a  number  of  hairs  were  subjected  to 
both  operations.  The  upper  part  of  the  follicle  was  removed,  the 
wound  allowed  to  heal,  and  then  the  lower  part  of  the  follicle 
was  exsected.  The  hair  was  then  little  more  than  a  bristle  set  in 
a  mass  of  scar  tissue. 

Removal  of  upper  and  lower  innervations  of  follicle  on  scrotum; 
when  tested  the  stimulus  was  applied  to  the  hair. 


M.  2  follicles ;  tested  24  hrs.  after  2d  operation.  Probably  slightly  sub¬ 
normal. 


4 

ii 

ii  -  .  ii  ii  ii 

a 

Probably  slightly  sub¬ 

normal. 

3  days  “  “ 

a 

Normal 

W.  3 

ii 

“  24  hrs.  “  “ 

a 

Slightly  subnormal 

4 

ii 

ii  ^  .  ii  ii  ii 

a 

Slightly  subnormal 

On  stimulating  such  hairs,  the  sensation  must  come  of  course 
from  the  skin  at  the  point  of  emergence.  The  scrotal  hairs  are 
well  isolated,  and  there  is  little  chance  of  diffusion  of  the  stimulus 
to  neighboring  follicles.  The  experiments  on  three  subjects  show 
that  the  removal  of  both  innervations  gives  the  same  result  as 
the  removal  of  the  upper  innervation.  There  is  every  reason  to 
assume  that  the  papilla  is  not  a  sensory  end-organ  of  any  sort. 

Removal  of  the  Entire  Follicle 

When  the  follicles  are  entirely  removed  from  a  hairy  surface, 
any  response  to  light  pressure  must  be  due  to  end-organs  in  the 
skin  surface. 

Areas  were  selected  on  the  scrotum  where  the  single  follicles 
are  well  defined;  the  skin  is  transparent  and  it  is  possible  to 
locate  and  extirpate  every  follicle  with  certainty.  The  follicles 
were  removed  entire.  The  wounds  were  small,  there  was  very 
little  reaction  (no  local  anesthesia  was  used)  and  the  healing  was 
very  rapid.  From  10  to  20  follicles  were  removed  from  each 
territory. 


14 


R.  H.  STETSON 


M.  An  area  2.5  sq.  cm.  was  cleared;  tested  24  hrs.  after  with 
probe  showed  some  insensitiveness.  Three  days  after,  tested 
carefully  with  the  v.  Frey  apparatus  it  was  impossible  to  detect 
any  change  of  the  intermediate  areas  within  the  denuded  territory. 
The  scars  themselves  were  slightly  less  sensitive. 

K.  3  sq.  cm.  Tested  three  days  after  clearing.  With  v.  Frey 
apparatus  no  difference  could  be  detected  save  in  the  scars  which 
were  much  below  normal. 

S.  2  sq.  cm.  Tested  12  hours  after  clearing.  ‘Pressure 
spots’  of  normal  territory  show  lower  threshold  (14)  than  in¬ 
termediate  areas  of  either  denuded  or  normal  territories.  Calls 
stimulation  of  normal  ‘pressure  spot’  “hair.”  Intermediate  areas 
give  the  same  reading  (17)  in  normal  and  denuded  skin.  Tested 
after  six  days,  the  ‘pressure  spots’  of  normal  territory  have 
lowest  threshold  (15);  intermediate  areas  in  both  normal  and 
denuded  skin  give  17.  The  pressure  spots  of  the  normal  areas 
are  easily  deformed.  The  scars  of  denuded  area  are  thickened, 
and  not  easily  deformed,  and  give  a  reading  of  19-22. 

L.  3  sq.  cm.  Tested  8  days  after  clearing.  No  difference 
could  be  detected  between  normal  and  denuded  territories,  save 
that  the  slightly  indurated  scars  were  less  sensitive.  The  dilute 
alcohol  used  for  asepsis  had  tanned  and  thickened  all  the  skin 
slightly. 

Ma.  3  sq.  cm.  Tested  5  days  after  clearing.  No  difference 
between  the  normal  and  denuded  territories,  save  that  the  scars 
which  do  not  deform  easily,  are  not  as  sensitive  as  other  areas. 
The  normal  ‘pressure  spots’  are  no  more  sensitive  than  the  in¬ 
termediate  areas;  they  do  not  deform  as  easily  as  in  the  case  of  S. 

W.  2  sq.  cm.  Tested  10  days  after  clearing.  No  difference 
between  the  normal  and  denuded  territories,  and  threshold  is  not 
lower  for  the  normal  ‘pressure  spots,’  which  do  not  deform  easily. 
The  thickened  scars  are  relatively  insensitive  and  do  not  deform 
readily. 

In  all  these  cases,  care  was  taken  to  test  out  several  localities 
within  and  without  the  denuded  territory,  and  to  select  places 
well  within  the  denuded  territory,  so  that  there  might  be  no  possi- 


THE  HAIR  FOLLICLE 


15 


bility  of  diffusion  of  the  stimulus  to  normal  end-organs.  The 
tissue  of  the  scrotum  is  so  yielding  and  flexible  that  such  trans¬ 
mission  is  improbable  in  any  case. 

In  these  cases  the  power  of  localization,  the  threshold  for  light 
touch  and  for  tickle  all  seemed  the  same  in  the  normal  and  in 
the  denuded  territories. 

In  the  various  operations  on  the  hair  follicle  it  is  noteworthy 
that  there  are  no  pain  endings  found  in  the  follicle.  On  the 
scrotum  there  are  no  pain  endings  to  be  found  in  the  subcutaneous 
fibres.  On  the  other  surfaces,  many  pain  endings  are  met  with 
in  the  subcutaneous  tissue.  The  scrotum  gives  but  little  pain 
sensation;  the  lower  arm,  lower  leg,  and  point  of  hip  are  about 
equally  sensitive;  the  leg  just  above  patella  gives  very  acute  pain 
sensation  and  few  subjects  are  able  to  bear  operations  there  with¬ 
out  local  anesthesia.  The  differences  in  the  sensitiveness  to  pain 
of  different  localities  is  very  striking. 

Examination  of  Extensive  Scars 

A  number  of  large  scars  where  the  skin  had  been  destroyed 
were  carefully  examined.  The  area  was  first  searched  for  traces 
of  follicles,  which  can  easily  be  detected  when  the  surface  is  rubbed 
down,  moistened,  and  examined  under  a  binocular  with  red  light. 
Nineteen  scars  on  17  subjects  were  studied.  The  scars  occurred 
on  various  parts  of  the  body  but  mainly  on  the  lower  leg  and 
lower  arm.  In  most  cases  the  threshold  for  pressure  was  below 
that  of  the  bordering  area;  this  varied  somewhat  with  the  thick¬ 
ness  of  the  scar  epidermis.  Localization  did  not  seem  to  be 
affected.  Two  scars  which  were  heavily  indurated  and  covered 
with  a  thickened  skin,  were  quite  insensitive,  and  did  not  give 
the  results  of  the  other  17. 

An  attempt  was  made  to  imitate  the  hair  sensation  on  these  19 
scar  areas.  Artificial  ‘hairs’  were  made  1)  by  inserting  a  fine 
elastic  needle  into  the  epidermis,  2)  by  cementing  onto  the  scar 
surface  a  bit  of  hair-spring  or  fine  wire  bent  at  the  base  into  a 
tiny  foot.  A  stimulator  consisting  of  a  bit  of  reduced  hair-spring 
tipped  with  a  little  ball  of  collodion  was  applied  with  quick  taps. 


i6 


R.  H.  STETSON 


In  17  cases,  on  as  many  subjects,  it  was  easy  to  imitate  hair 
sensations,  so  that  the  subject  could  not  tell  the  false  ‘hairs’  from 
the  normal  hairs  of  the  bordering  areas.  The  confusion  was 
complete. 

Artificial  ‘hairs’  were  mounted  on  three  trained  subjects  on  the 
back  of  the  hand  between  the  normal  hairs.  It  was  impossible  to 
discriminate  the  false  from  the  normal  hairs. 

Artificial  ‘hairs'  were  mounted  on  three  trained  subjects  on  the 
hairless  palmar  area  (at  ball  of  thumb  on  outer  edge  of  hand) 
near  the  hairy  area,  and  compared  with  normal  hairs.  Subjects 
were  quite  unable  to  distinguish  between  the  false  and  the  normal 
hairs. 

These  experiments  with  artificial  hair  sensations  on  scars  and 
on  the  hairless  areas  tend  to  show  that  the  hair  sensation  has  no 
peculiar  quality,  but  may  be  due  entirely  to  the  deformation  of 
the  skin  surface,  in  the  absence  of  hair  follicles.  In  general  the 
artificial  ‘hairs’  seemed  to  give  a  less  intense  sensation;  but  there 
was  no  qualitative  difference.  In  such  work  the  method  of  ask¬ 
ing  the  subject  to  discriminate  between  the  real  and  the  artificial 
stimulus  gives  convincing  results;  it  is  capable  of  extension  to 
other  types  of  skin  sensation. 

Conclusions 

The  hair  as  a  sensory  apparatus  is  like  a  willow  shoot  deeply 
rooted  in  loose  sand.  When  the  hair-shaft  is  moved  the  move¬ 
ment  is  greatest  at  the  surface;  pressure  is  exerted  on  the  neural 
rings,  etc.,  which  make  up  the  upper  innervation  of  the  follicle; 
often  there  is  compression  of  the  rings  between  the  hair  follicle 
and  the  surface;  at  the  same  time  the  surface  of  the  skin  at  the 
point  where  the  hair  emerges  is  freely  moved. 

It  is  practically  certain  that  the  lower  innervation  of  the 
papilla  of  the  hair  is  not  a  sensory  organ.  The  sensation  of  the 
hair,  then,  results  from  1 )  the  compression  of  the  upper  innerva¬ 
tion  (b  in  fig.  3)  and  2)  from  the  deformation  of  the  skin 
surface  at  the  point  of  emergence  (a  in  Fig.  3).  There  is  no 
qualitative  difference  between  the  two  factors. 


THE  HAIR  FOLLICLE 


1 7 


When  pressure  is  applied  to  the  ‘pressure  spot/  the  resulting 
stimulus  is  complex :  i )  there  is  stimulation  of  the  skin  surface 
at  the  point  (a  in  Fig.  3),  2)  compression  of  the  upper  innerva¬ 
tion  of  the  follicle  (b  in  Fig.  3),  and  3)  deformation  of  the 
skin  at  the  point  of  emergence  by  the  pressure  transmitted  by 
the  hair-shaft  (a  in  Fig.  3). 

Tests  of  denuded  areas  and  of  scars  show  that  hair  follicles 
are  not  essential  to  any  variety  of  pressure  or  touch  sensation, 
and  that  the  threshold  for  pressure  is  but  slightly  lowered  by  the 
removal  of  the  follicles. 

In  the  hairy  areas  the  end-organs  for  touch,  then,  are  not  con¬ 
fined  to  the  hair  follicles,  but  are  found  throughout  the  skin  sur¬ 
face,  and  they  are  regenerated  in  epithelial  scar  tissue.  The  in¬ 
nervation  of  the  hair  papilla  is  not  a  sensory  end-organ.  The 
hair  follicle  is  not  furnished  with  endings  for  pain. 


MECHANISM  OF  THE  DIFFERENT  TYPES 

OF  MOVEMENT 


R.  H.  Stetson 

WITH  A  PRELIMINARY  REPORT  OF  EXPERIMENTAL  DATA 

James  A.  McDill 

The  fundamental  thing  in  the  process  called  a  movement  is 
the  muscular  contractions;  the  extent  of  actual  change  of  position 
of  the  member  involved  depends  on  conditions.  The  movement 
of  the  member  is  the  usual  purpose  of  muscular  action  and  move¬ 
ment  is  often  taken  as  the  index  of  muscular  action.  In  rapid, 
repeated  movements  it  is  probable  that  change  of  position  of  the 
moving  member  is  of  importance  in  the  cycle  of  neuro-muscular 
changes  on  which  innervation  and  coordination  depend. 

In  the  action  of  muscles  against  immovable  or  slowly  moving 
resistance  the  individual  muscular  impulses  are  difficult  to  detect 
and  the  nature  of  the  reaction  is  obscured.  In  the  following  dis¬ 
cussion  such  actions  are  not  considered.  Movements  are  defined 
as  reactions  in  which  the  contraction  of  the  muscles  affect  the 
position  of  the  moving  member. 

Classification  of  Movements 

1.  Fixation;  in  which  groups  of  opposing  muscles  are  con¬ 
tracted  against  each  other.  This  is  the  movement  of 
holding  still. 

2.  The  slow  movement;  in  which  the  groups  of  opposing 
muscles  are  contracted  but  with  uneven  tension  so  that 
change  of  position  of  the  moving  member  results.  Often 
called  the  “controlled  movement”  because  it  can  be  changed 
at  any  point  in  its  course. 

3.  The  rapid  movement;  which  cannot  be  changed  at  every 
point  in  its  course  but  is  usually  determined  entirely  be¬ 
fore  the  movement  begins.  The  movement  is  a  matter 


18 


MECHANISM  OF  THE  DIFFERENT  TYPES 


19 


of  preliminary  set,  “Einstellung.”  Two  kinds  of  rapid 
movement  may  be  distinguished. 

A.  Movements  in  which  there  is  a  tension  in  all  the 
opposing  muscle  groups  throughout  the  movement. 

B.  Movements  in  which  the  contraction  of  the  positive 
muscle  group  relaxes  long  before  the  end  of  the 
movement;  the  termination  of  the  movement  may 
be  due  to  the  contraction  of  the  antagonistic  muscles. 
This  kind  of  movement  was  named  by  Richer  “ball¬ 
istic'’  because  the  moving  member  is  actually  free 
from  muscular  tension  in  the  middle  of  its  course 
and  is  carried  on  by  its  own  momentum. 

I.  Fixation — The  Movement  of  Holding  Still. 

All  the  various  fixations  of  joints  and  members  are  of  this 
type.  Every  ordinary  distal  movement  requires  a  proximal  fixa¬ 
tion.  Postures  are  of  course  movements  of  holding  still.  Re¬ 
cent  work  has  shown  that  “muscle  tonus’’  is  merely  a  posture 
reflex.1  • 

A  record  of  the  movement  of  holding  still,  as  of  a  hand  holding 
stylus  or  of  a  finger  tipped  with  writing  point,  shows  that  the 
member  is  only  approximately  at  rest.  The  member  describes  to- 
and-fro  movements  about  a  center.  In  a  common  form  of  the 
“steadiness  test,”  a  stylus  is  held  in  holes  of  varying  diameter 
and  the  extreme  amplitude  of  the  movement  determined.  For 
the  purpose  of  comparing  and  relating  types  of  movement  the 
number  of  tremors  per  second  is  more  important  than  the  ampli¬ 
tude.  Lueiani  notes  such  a  definite  tremor  in  case  of  an  out¬ 
stretched  arm.2  He  quotes  Richet  as  giving  10-11  per  sec.  as 
the  frequency  of  tremor.  F.  B.  Dresslar  studying  rapid  volun¬ 
tary  movement  determined  the  tremor  of  the  members  involved . 
Forearm — 12.2.  per  sec. 

Wrist,  lateral — 12.9  per  sec.3 

1  Sherrington,  C.  S.  Postural  activity  of  muscles  and  nerves,  Brain,  38,  ’15, 
191.  Langelaan,  J.  W.  On  muscle  tonus,  ibid.,  235. 

2  Human  Physiology  (’13)  ’i5>  5^3- 

3  Some  influences  which  affect  the  rapidity  of  voluntary  movements,  Am. 

J.  Psy.  4,  ’9i -’92,  514- 


20 


R.  H.  STETSON  AND  JAMES  A.  MC  DILL 


It  has  been  assumed  that  this  muscular  tremor  denotes  the 
rate  of  synaptic  reflex  discharge  through  the  motor  nerve  into 
muscles.  Luciani  quotes  Horseley  and  Schafer,4  and  Sherrington 
quotes  Schafer;5  but  more  recent  studies  have  made  it  clear  that 
this  unit  of  muscular  movement  cannot  be  referred  directly  to 
the  frequency  of  impulses  in  the  motor  nerve.6  The  reflex 
motor  nerve  frequency  is  given  as  50-150  per  sec.  And  it  is 
noted  that  there  are  3-4  neural  impulses  for  each  muscle  twitch. 
It  is  true  that  tetanus  occurs  in  skeletal  muscle  if  the  frequency 
of  the  sensory  stimuli  is  greater  than  15  per  sec.,7  but  this  does 
not  mean  that  there  is  a  single  motor  impulse  for  each  sensory 
stimulus;  instead  there  is  a  train  of  motor  impulses  for  each 
sensory  stimulus.8 

For  some  time  the  attention  of  investigators  was  centered  on 
this  frequency  of  c.50  per  sec.  as  indicated  by  the  action  currents 
from  the  muscles.  Recently  De  Meyer  has  published  a  series  of 
studies  in  which  he  points  out  that  the  curves  of  previous  in¬ 
vestigators  show  other  and  lower  frequencies  superimposed  on 
the  c.50  per  sec.  rate.  Laboratory  work  shows  that  there  are 
currents  of  deformation  of  muscle  due  to  any  lengthening  or 
shortening  of  muscle,  as  well  as  action  currents  due  presumably 
to  chemical  changes  in  the  myofibrillae.9  The  lower  frequencies 
noted  by  De  Meyer  are  of  the  order  of  10  per  sec.,  and  are  prob¬ 
ably  to  be  identified  with  tremor. 

One  might  be  inclined  to  say  that  the  chemical  changes  which 
register  themselves  in  action  currents  did  not  appear  as  actual 

4  Ibid.,  562. 

5  Integ.  Act.  N.  Sys.  206. 

6  Beritoff,  J.  S.  Zschr.  f.  Biol.,  64,  ’14,  161 ;  and  Piper,  Arch.  f.  Anant.  u. 
Phys.,  Ph.  Abt.,  ’14,  345;  (Cited  Gen.  Rev.,  Psy.  Bull.,  ’16.) 

7  Starling,  Prins.  of  Hum.  Physiol.,  ’12,  228. 

8  Beritoff,  Ub.  d.  Erregungsrhythmik  d.  Skelettenmuskeln  b.  refl.  Innerva¬ 
tion,  Zschr.  f.  Biol.  64,  ’14,  161.  Lucas,  Keith,  The  Conduction  of  the  Nerve 
Impulse,  Lond.  ’17. 

9  De  Meyer,  J.  D.,  Des  differents  sources  de  courants  electriques  des  systemes 
musculaires,  p.  44.  Sur  les  courants  de  deformation  des  muscles,  p.  64.  De 
la  dualite  d’origine  des  courants  electriques  produits  par  les  muscles  stries, 
p.  173.  Arch,  internat.  de  physiol.  16,  ’21. 


MECHANISM  OF  THE  DIFFERENT  TYPES 


21 


movements  of  the  gross  muscle,  but  merely  as  phenomena  within 
the  fiber.  But  the  work  of  Hill  using  a  direct  record  from  the 
moving  muscle  (air  tambour,  hot  wire  to  string  galvanometer) 
shows  that  the  rate  of  c.50  per  sec.  does  appear  in  the  movement 
of  the  member.  It  is  difficult  to  imagine  how  the  multitude  of 
minute  neuro-muscular  processes  can  be  kept  in  phase  so  that 
this  rate  is  impressed  on  the  mass  movement,  but  the  records  are 
very  clear.  However,  a  second  and  lower  frequency  to  which 
Hill  does  not  call  attention  is  very  obvious  in  his  published  curves. 
There  is  too  little  material  to  make  a  very  definite  calculation, 
but  apparently  this  lower  frequency  is  c.io  per  sec.  and  cor¬ 
responds  to  the  slower  frequencies  emphasized  by  De  Meyer.10 

Although  nothing  can  be  said  as  to  the  nature  of  this  tremor 
frequency  there  is  good  reason  for  assuming  that  it  marks  the 
period  of  a  unit  of  movement.  Starling  has  shown  that  the 
duration  of  the  cycle  of  the  muscle  twitch  at  the  ordinary  tem¬ 
perature  is  c.  100-180  sig.,  6-10  per  sec.11  In  fibrillation  of  the 
muscle,  a  study  of  the  continuous  series  of  contractions  shows 
that  the  rate  of  the  fibrillar  cycle  is  10-20  per  sec.12  This  unit 
movement  appears  in  the  various  combinations  which  make  up 
the  types  of  movements. 

2.  Slow  or  “Controlled”  Movements. 

If  the  movement  of  holding  still  be  extended  in  a  given  direc¬ 
tion,  it  is  evident  that  the  beginning  of  the  extension  will  be  a 
tremor.  If  the  attempt  be  to  make  a  very  small  movement,  the 
extent  of  a  tremor  will  determine  the  extent  of  the  movement 
which  must  consist  of  two  or  more  tremors.  The  ability  to  make 
movements  more  and  more  minute  is  not  limited  by  sensory 
methods  of  control,  but  by  this  fundamental  tremor  element  of 
muscular  action.13 

10  Hill,  A.  V.,  Tetanic  nature  of  the  voluntary  contraction  in  man,  J.  Phys., 

55,  f2i,  xiv. 

11  Ibid. 

12  Stevens,  H.  C.,  The  cause  of  muscular  atrophy  following  nerve  sec.  J. 
Am.  Med.  Ass.  60,  T8,  385. 

13  Work  of  L.  T.  Anderegg  and  J.  Merle  Scott  in  the  Oberlin  laboratory 


22 


R.  H.  STETSON  AND  JAMES  A.  MC  DILL 


When  the  movement  is  not  so  minute  as  to  be  limited  by  a 
few  tremor  lengths  it  is  still  apparent  that  the  tremor  impulses 
are  present.  Luciani  states  that  a  record  of  slow  voluntary  con¬ 
traction  of  any  muscle  (e.g.  the  opponens  of  the  thumb)  shows 
undulations  which  are  fairly  regular  in  frequency — though  irregu¬ 
lar  in  amplitude' — c. 10-12  per  sec.  He  quotes  Griffiths’  statement 
that  an  increase  in  frequency  to  15-18  per  sec.  results  when  a 
load  is  applied  to  the  moving  member.14 

Like  the  movement  of  holding  still,  a  slow  movement  is  due  to 
the  contraction  of  opposing  muscles.  In  its  simplest  form  the 
progress  of  the  movement  results  from  tremor  increments  in  one 
of  the  muscle  groups.  Since  the  movement  elements  occur  as 
frequently  as  10  per  sec.  and  since  the  increment  is  very  slight, 
developing  little  or  no  momentum  in  the  moving  member,  the 
movement  can  be  changed  at  any  movement  element  (tremor). 
No  neuro-muscular  provision  is  made  in  advance  for  the  control 
of  the  movement.  The  slow  movement  is  probably  due  to  a  series 
of  slight  increases  in  the  algebraic  sum  of  the  number  of  muscle 
fibers  contracting  in  the  positive  muscle  group  as  against  the 
number  of  fibers  contracting  in  the  antagonistic  muscle  group. 
This  type  of  slow  movement  has  been  described  and  the  essential 
difference  in  its  mechanism  from  that  of  the  fast  movement  has 
been  discussed  by  Richer.15  The  sharp  difference  in  type  between 
fast  and  slow  movements  of  the  eyeball  has  been  repeatedly 
noted.16 

3.  Fast  Movements. 

As  a  slow  movement  is  increased  in  speed,  the  movement 
elements  will  be  stretched  out;  their  frequency  remains  the  same 
but  there  will  be  fewer  undulations  per  unit  of  length.  For  a 

shows  that  magnification  of  the  visual  field  does  not  improve  the  delicacy  of 
minute  movement.  Quite  as  minute  movements  can  be  made  without  the 
eyes  as  with  normal  vision  or  with  magnification. 

14  Ibid.,  562. 

15  D’Arsonval  et  autres,  Traite  de  physique  biologique,  ’01,  Tome  I,  156, 

16  Gertz,  H.,  lib.  d.  gleitende  (langsame)  Augenbewegung,  Zschr.  f.  Ps.  u. 
Ph.  d.  S.  Abt.  2,  (1 ),  49,  T4,  15.  Dodge,  R.,  Psy.  Rev.  7,  ’00,  454.  Dodge,  R., 
and  Cline,  T.  S.,  Psy.  Rev.  8,  ’01,  155. 


MECHANISM  OF  THE  DIFFERENT  TYPES 


23 


path  of  given  length  a  speed  should  be  possible  at  which  the 
entire  movement  shall  be  a  single  stretched-out  movement  ele¬ 
ment.  d  he  movement  will  now  be  a  smooth  curve,  a  single  un¬ 
dulation.  The  control  of  the  movement  will  depend  on  a  single 
impulse  in  the  one  group  of  muscles  which  starts  the  movement 
and  on  the  intervention  of  a  second  impulse  in  the  antagonistic 
muscle  group  which  stops  the  movement  (if  it  is  a  free  move¬ 
ment  without  obstacle,  like  beating  a  baton  in  the  air,  writing, 
rapid  shifting  of  the  eyeball,  etc.) 

It  is  now  apparent  that  such  a  rapid  movement  cannot  be  sub¬ 
ject  to  control  after  it  is  once  started;  movement  elements  occur- 
ing  at  the  rate  of  10  per  sec.  are  the  units;  at  most  then  move¬ 
ments  can  be  modified  not  oftener  than  ten  times  in  a  second.  A 
movement  occurring  at  the  rate  of  10  per  sec.  and  consisting  there¬ 
fore  of  a  single  movement  element  and  terminated  by  the  follow¬ 
ing  movement  element  must  be  the  result  of  an  adjustment  pre¬ 
ceding  the  entire  movement.  The  movement  at  maximum  rapidity 
is  controlled  by  a  preliminary  “set,”  “Einstellung.” 

A.  Fast  Movement  under  Tension. 

If  the  fast  movement  be  considered  as  developed  from  the 
position  of  fixation  of  the  moving  member  the  movement  may 
be  due  to  a  sudden  excess  contraction  of  one  of  the  groups  of 
muscles  making  up  the  complex  of  muscle  groups  involved  in 
holding  still,  followed  by  an  excess  contraction  in  the  antagonistic 
muscle  group  which  stops  the  movement.  A  movement  of  trans¬ 
lation  is  thus  superimposed  on  the  fixation,  and  the  movement 
occurs  under  tension.  Not  only  are  the  muscles  contracted 
which  have  to  do  with  guiding  the  movement  (Du  Bois  Rey- 
mond’s  pseudantagonistic  synergie)  but  the  positive  muscle  group 
and  the  antagonistic  muscle  group  also  maintain  a  tension  against 
each  other  throughout  the  movement. 

B.  The  Ballistic  Movement. 

The  ballistic  movement  is  a  common  form  of  the  fast  move¬ 
ment;  it  consists  of  a  single  unit  contraction  of  the  positive  muscle 


24 


R.  H.  STETSON  AND  JAMES  A.  MC  DILL 


group  followed  by  a  unit  contraction  of  the  antagonistic  muscle 
group.  The  moving  member  is  not  under  tension  from  both 
muscle  groups;  the  movement  of  translation  is  not  superimposed 
on  a  fixation.  Instead,  a  single  tremor  impulse  of  the  positive 
muscle  group  starts  the  movement;  the  contraction  of  this  im¬ 
pulse  dies  out  before  the  second  tremor  impulse  of  the  antagonistic 
muscle  group  appears  to  check  the  movement.  There  is  therefore 
a  median  part  of  the  movement  in  which  the  moving  member 
swings  free  carried  by  its  own  momentum.  There  may  be  fix¬ 
ation  of  a  joint  and  there  is  the  guiding  tension  of  muscle  groups 
which  determine  the  path  of  the  movement,  but  there  is  no  op¬ 
posing  tension  to  the  flight  of  the  moving  member.17 

In  a  to-and-fro  movement  at  maximum  speed  the  unit  con¬ 
traction  which  checks  the  one  movement  becomes  the  driving  im¬ 
pulse  for  the  reverse  movement,  relaxing  before  the  positive  unit 
contraction  reappears  to  check  the  reverse  movement  and  start 
the  moving  member  on  its  second  flight.  Such  a  to-and-fro  move¬ 
ment  ought  to  approach  very  close  to  the  tremor  rate  as  indeed 
it  does.  F.  B.  Dresslar’s  observation  that  the  maximum  rate  of 
tapping  is  c.10.5  per  sec.,  while  the  tremor  rate  for  forearm  and 
wrist  is  12.2  and  12.9  respectively  should  have  been  taken  as 
evidence  that  the  two  values  are  closely  related  and  not  that  they 
are  due  to  distinct  processes.18 

T.  G.  Brown  makes  the  fundamental  unitary  mechanism  to 
consist  of  the  efferent  neurones  of  two  antagonistic  muscles.19  It 
is  possible  that  the  maximum  rapidity  of  a  repeated  movement 
is  limited  by  the  rate  at  which  excitation  and  inhibition  can  be 
developed  in  two  antagonistic  muscle  groups.  If  one  assumes 
that  inhibition  is  due  to  the  combination  of  trains  of  excitation 
in  pulses  in  the  motor  nerves  (K.  Lucas,  Verworn,  etc.)  it  may 
well  be  that  the  overlapping  of  the  series  to  produce  the  con¬ 
tinuous  refractory  condition  followed  by  the  normal  conducting 
condition  has  a  definite  time  limit.  It  is  probable  that  the  me- 

17  Richer,  P.,  loc  cit. 

18  Some  influences  which  affect  the  rapidity  of  voluntary  movements,  Am. 
J.  Psy.  4,  ’91-92,  514. 

19  J.  Physiol.  48. 


MECHANISM  OF  THE  DIFFERENT  TYPES 


25 


chanical  change  due  to  movement  is  an  important  factor  in  the 
coordination. 

The  fast  movement  under  tension  and  the  ballistic  movement 
have  not  always  been  distinguished.  But  in  many  types  of  skilled 
movement  the  distinction  is  important.  In  piano  playing,  in 
violin  playing,  and  in  telegraphy  the  contrast  between  the  “tight” 
or  “stiff”  rapid  movement  (fast  movement  under  tension)  and 
the  “loose”  rapid  movement  (ballistic)  has  come  to  be  a  com¬ 
monplace.  Piano  technic  has  been  recognized  during  the  past 
thirty  years  on  that  basis. 

At  the  highest  rate  of  repetition  there  can  still  be  variation 
from  movement  to  movement  if  not  during  the  flight  of  any  single 
movement.  Although  the  duration  is  fixed  the  extent  of  such 
movements  is  subject  to  wide  variation.  This  has  been  noted  in 
several  movement  studies.20  The  ballistic  movement  is  capable 
of  the  most  delicate  adjustment,  in  extent  as  in  the  case  of  writ¬ 
ing  and  keyboard  manipulation,  and  in  force  as  in  case  of  dynamic 
shading  in  violin  or  piano  playing,  singing,  speech,  etc. 

Since  the  duration  of  the  rapid  movement  is  fixed,  there  can 
be  but  two  variables,  extent  and  force.  This  limits  somewhat 
the  problem  discussed  by  Morgan  and  Goerrig.21 

Experimental  Results. 

Tremors  in  fixation  of  finger — movement  of  holding  still. 

The  right  hand  was  supported  on  table  in  comfortable  position. 
A  writing  point,  the  point  of  a  sharp  needle,  was  fastened  to  the 

20  Stetson,  R.  H.,  Theory  of  rhythm  and  discrete  succession,  Psy.  Rev.  12, 
’05,  261.  Isserlin,  M.,  Ub.  d.  ablauf  einfacher,  willkiirlicher  Bewegungen,  Psy. 
Arb.  6  (1),  1910-14,  86,  who  states  clearly  that  the  total  duration  of  rapid 
movements  remains  the  same  for  a  given  person  no  matter  what  the  extent 
of  the  movement.  Freeman,  F.  N.,  Anal,  of  the  writing  movement,  Psy. 
Mon.  Sup.  17,  T4,  No.  4,  1-46,  who  confirms  Binet  and  Courtier  in  statement 
that  in  case  of  rapid  writing  movements  the  increase  of  extent  of  a  single 
movement,  or  of  the  writing  as  a  whole,  does  not  mean  an  increase  in  duration 
of  the  stroke  or  strokes,  but  rather  increase  in  speed;  the  time  of  rapid  writing 
is  independent  of  its  size. 

21  Morgan,  J.  B.,  The  speed  and  accuracy  of  motor  adjustments,  J.  Xp.  Psy. 
2,  T 7,  225.  Goerrig,  M.  A.,  Einfluss  d.  Zeitdauer  auf  d.  Grossenschatzung  v. 
Armbewegung,  Arch.  f.  d.  ges.  Psy.  36,  T 7,  293. 


26 


R.  H.  STETSON  AND  JAMES  A.  MC  DIED 


nail  of  the  index  finger.  The  other  fingers  and  thumb  rested  on 
the  table  while  this  index  finger  was  held  extended  with  the  writ¬ 
ing  point  in  contact  with  a  smoked  glass  slide  perpendicular  to 
the  table,  so  that  the  finger  movements  were  recorded  in  the 
vertical  plane.  A  Jacquet  chronograph  marking  fifths  of  sec. 
on  the  slide  afforded  a  record  of  time  intervals.  The  glass  slide 
was  drawn  in  a  groove  by  a  thread  winding  on  a  kymograph  drum 
running  at  rather  slow  speed. 

The  records  were  measured  under  a  Zeiss  binocular  micro¬ 
scope.  To  avoid  errors  each  change  in  direction  was  counted 
and  the  result  divided  by  two.  The  slides  were  labeled,  the 
smoked  record  mounted  with  cover  glass  and  balsam  in  the  usual 
manner. 


Subject  W  Record  of  9  seconds;  average  per  sec. 

6.8 

Mean  variation  .8 

13 

8.2 

1. 

7 

8.2 

1. 1 

8 

8.1 

1. 1 

S 

7-8 

i-3 

10 

7-7 

.7 

10 

7-7 

•9 

*-r 

✓ 

7-3 

.8 

8 

6-5 

•9 

1 1 

7-3 

•5 

4 

7- 

•9 

Subject  A  5 

74 

•9 

Subject  N  7 

8. 

1.5 

Subject  D  5 

6.9 

•3 

These  records  show  a  fairly  definite  frequency  which  varies 
somewhat  from  sitting  to  sitting  and  from  subject  to  subject. 
The  mode  is  c.7.5  per  sec.  which  is  somewhat  lower  than  other 
results  but  not  significantly  so. 

Tremor-undulations  in  various  types  of  movement  at  various 
speeds : 

Short,  straight  lines  of  3-4  mm.  were  drawn  with  the  ordinary 
writing  movement  of  fingers  and  hand  at  speeds  varying  from 
14-160  per  minute. 

Longer  lines  of  440  mm.  were  drawn  with  pencil  by  movements 
of  the  forearm  and  upper  arm,  at  speeds  varying  from  14-160 
per  minute. 


MECHANISM  OF  THE  DIFFERENT  TYPES 


27 


The  short  lines  of  3-4  mm.  were  drawn  on  smoked  glass  slides, 
the  click  of  a  metronome  indicating  the  beginning  and  end  of 
the  parallel  lines.  There  are  several  sources  of  possible  variation : 
the  speed  of  the  movement  may  vary,  and  the  movement  may 
not  occur  within  the  indicated  time  interval.  As  the  movements 
are  repeated  and  rhythmic,  these  variations  are  limited  and  tend 
to  compensate.  The  lines  were  measured  under  the  microscope 
and  averaged  in  groups  of  30. 


Subject  A 


30  lines, 

14  lines  per  min. 

4.28  sec.  per  stroke, 

10. 1  undulations  per  sec. 

m.v.  1. 1 

30 

22 

2.72 

12.2 

2.4 

30 

48 

1.25 

15-3 

1. 1 

30 

60 

1. 

12.3 

1.6 

30 

70 

.86 

11  -7 

1.4 

30 

80 

75 

11.2 

i-4 

30 

90 

.67 

11.4 

1  -7 

30 

100 

.60 

10.5 

14 

30 

no 

•54 

9.8 

2. 

30 

120 

•50 

9.8 

1.8 

30 

130 

.46 

10.6 

2.1 

30 

140 

.42 

11. 1 

2.2 

30 

150 

.40 

II-5 

1-9 

30 

160 

•37 

n-3 

1.8 

Although  there  is  considerable  variation,  it  is  clear  that  the 
“undulation”  marks  some  definite  frequency  which  remains  fairly 
constant  throughout  the  series.  This  tremor  undulation  indicates 
some  fairly  constant  element  in  the  movement;  it  is  possible  that 
the  record  is  of  impulses  in  the  “pseudantagonistic”  muscle  groups 
rather  than  in  the  driving  muscles ;  but  slow  movements  like  that 
of  closing  the  fingers  show  that  driving  muscles  also  have  the 
same  pulses.  Although  these  movements  are  approximately  of 
the  same  length,  the  slowest  movement  has  an  average  of  43  of 
these  elements,  and  the  fastest  movement  has  an  average  of  4. 

The  longer  lines  of  440  mm.  were  drawn  between  limiting  per¬ 
pendicular  lines  on  smooth  cardboard  sheets  with  a  hard  pencil ; 
the  beginning  and  the  end  of  the  line  was  indicated  by  metronome 
click.  In  studying  the  lines,  the  sheets  were  placed  on  inclined 
plane  to  bring  one  end  nearer  the  eye;  by  “squinting”  down  the 
fore-shortened  line  the  undulations  could  be  counted. 


28 


R.  H.  STETSON  AND  JAMES  A.  MC  DILL 


30  lines. 

Subject  P 

8.4  lines  per  min.  4.4  undulations  per  sec. 

M.v.  .9 

30 

14 

5-6 

.8 

30 

22 

6. 

30 

42 

6.9 

30 

48 

79 

2. 

30 

60 

7.6 

1.7 

30 

70 

8.2 

30 

80 

7-7 

30 

90 

8. 

30 

100 

8.2 

30 

no 

8.6 

30 

120 

8.3 

30 

130 

77 

30 

140 

8.1 

30 

150 

8.1 

30 

160 

8.1 

2.2 

There  is  more  variation 

from  rate  to  rate  than 

in  the  record 

of  short  lines;  the  mean  variation  at  a  given  speed  is  about  the 
same  as  for  the  shorter  lines.  It  is  to  be  expected  that  the  fre¬ 
quency  of  the  tremor-undulation  would  be  somewhat  slower  when 
larger  muscles  are  involved ;  it  is  a  familiar  fact  that  the  maximum 
rate  of  larger  muscles  is  slower. 

Certain  difficulties  are  involved  in  starting  and  stopping  at  a 
limiting  line  when  drawing  lines  by  the  above  method.  To  avoid 
these  difficulties  a  series  was  made  in  which  the  pencil  was  in 
motion  when  passing  the  limiting  lines ;  a  flying  start  and  a  flying 

Subject  M. 

30  lines.  14  lines  per  min.  4.2  undulations  per  sec.  M.v.  1.1 


30  22  5.8 

30  48  9-5 

30  60  6. 

30  70  6.2 

30  80  6.8 

30  90  6.8 

30  100  7.8 

30  no  6.9 

30  120  6.2 

30  130  6.8 

30  140  7.3 

30  150  6.8 

30  160  7.2 


2.4 


MECHANISM  OF  THE  DIFFERENT  TYPES 


29 


stop.  A  possible  source  of  error  may  lie  in  the  varying  accuracy 
with  which  the  subject  drew  the  pencil  across  the  limiting  lines 
on  the  click  of  the  metronome.  The  length  of  line  measured  was 
300  mm. ;  the  number  of  undulations  was  counted  as  before. 

These  records  of  tremor  frequencies  agree  very  well  with  ma¬ 
terial  previously  published.  But  there  are  too  few  subjects  for 
the  various  types  of  movement.  There  are  records  from  only 
three  for  the  study  of  tremor  in  fixation,  records  from  only  two 
for  the  study  of  the  longer  movements,  and  records  from  only 
one  subject  for  the  study  of  small  movements.  The  results  al¬ 
though  insufficient  are  fairly  consistent  and  indicate  a  single  unit 
frequency  in  all  sorts  of  movements  at  varying  speeds.  This  unit 
frequency  is  very  close  to  the  maximum  frequency  of  voluntary 
movement  for  the  given  groups  of  muscles. 

The  Termination  of  Skilled  Movements. 

The  purpose  of  many  skilled  movements  is  achieved  at  the  end 
of  the  stroke;  there  the  work  is  performed,  the  blow  struck. 
Although  the  entire  path  of  the  movement  is  important  in  the  case 
of  a  few  movements  like  writing,  drawing,  use  of  surface-work¬ 
ing  tools  and  some  phases  of  musical  conducting,  yet  for  such 
movements  there  is  always  a  definite  termination. 

The  terminations  of  movements  may  be  classed  as  follows : 

1.  The  moving  member  swings  loose  about  joint;  movement 
is  terminated  by  ligaments  and  passive  muscles. 

2.  The  moving  member  is  arrested  by  the  antagonistic  mus¬ 
cle  group. 

3.  The  moving  member  is  arrested  by  an  obstacle,  a  “block.” 

1.  The  form  of  movement  in  which  the  moving  member  is 
brought  to  a  stop  by  the  ligaments  and  passive  muscles  is  rather 
unusual;  the  movement  of  the  hand  in  plucking  the  balalaika 
and  the  swing  in  golf  are  illustrations.  In  pitching  a  baseball 
the  muscles  are  brought  into  play  enough  to  hold  the  arm  in 
position  after  the  delivery  but  the  termination  of  the  movement 
is  due  primarily  to  the  passive  tissues  about  the  shoulder  joint. 

2.  The  moving  member  is  brought  to  a  stop  by  the  antago- 


30 


R.  H.  STETSON  AND  JAMES  A.  MC  DILL 


nistic  muscle  group  in  the  “free”  or  self-limiting  movement. 
The  movements  are  often  executed  in  the  air  without  any  re¬ 
sistance  as  are  most  gestures  and  the  movements  of  the  orchestra 
conductor.  All  the  movements  of  the  eyeball  are  self-limiting. 
Many  calisthenic  and  athletic  exercises  involve  such  movements 
either  untrammelled  or  against  a  slight  resistance.  Auxiliary  arm 
movements  in  walking,  running,  and  dancing  are  quite  free. 
Club  swinging,  and  wand  drills  involve  movements  against  a 
slight  resistance.  In  rowing  and  swimming  the  resistance  is  more 
pronounced  but  the  end  of  the  movement  is  determined  by  the 
opposing  muscles.  The  movements  of  writing  and  drawing 
meet  a  slight  resistance;  surface  working  tools  involve  varying 
degrees  of  resistance.  In  speech  repeated  vowels  and  liquids  re¬ 
quire  self-limiting  movements  of  large  muscles.  Violin  bowing 
and  the  manipulation  of  the  slide  trombone  involve  self-limiting 
movements  against  a  slight  resistance.  In  plucking  the  harp  or 
guitar  string  the  movement  creates  a  sharp,  elastic  resistance,  re¬ 
leases  it  and  passes  to  a  limit  fixed  by  the  muscles  themselves. 

Only  a  few  self-limiting  movements  are  terminated  by  the 
contraction  of  the  antagonistic  muscle  group  acting  directly 
against  the  contraction  of  the  positive  muscle  group.  Slow  move¬ 
ments  of  the  “controlled  type,”  are  stopped  by  the  increased  ten¬ 
sion  of  the  antagonistic  muscles  and  there  is  little  momentum  to 
be  taken  up. 

Wherever  the  movement  must  be  delicately  gauged  as  to  point 
in  time,  degree  of  force,  or  exact  form  of  movement  a  fast, 
“ballistic”  movement  is  used;  the  “back  stroke”  and  the  pre¬ 
paration  for  the  movement  may  be  slow  and  there  may  be  long 
pauses  between  “beat  strokes,”  but  the  stroke  itself  is  a  fast 
movement.  If  the  ballistic  movement  comes  to  rest  at  its  ter¬ 
mination,  there  is  a  fresh  contraction  of  the  positive  muscle  group 
with  other  muscles  involved  in  maintaining  the  position  of  the 
member.  Repeated  movements  at  maximum  speed  show  no 
period  of  standstill;  the  end  of  the  movement  presents  a  remark¬ 
ably  sharp  angle.  The  flight  of  the  moving  member  initiated  by 
the  positive  muscle  impulse  meets  the  gradually  increasing  ten¬ 
sion  of  the  antagonistic  muscle  group  which  reverses  it.  The 


MECHANISM  OF  THE  DIFFERENT  TYPES 


3i 


change  of  direction  is  almost  instantaneous  like  the  rebound  of 
an  ivory  ball  from  a  hard  surface,  or  of  a  light  weight  with  an 
elastic  spring.  Rieger  observed  this  rebound  and  referred  it  to 
the  positive  muscle  group.22  Isserlin  is  right  in  objecting  to  this 
interpretation  but  wrong  in  assuming  that  a  pause  must  intervene. 
It  is  quite  true  that  in  repeated  fast  movements  there  is  a  definite 
“relaxation”  process  in  the  sense  that  the  momentum  of  the 
moving  member  must  be  taken  up  and  the  contraction  of  the 
antagonistic  muscle  group  developed;  but  in  the  swifter  ballistic 
movements  the  moving  member  is  descending  and  rising  without 
pause  during  this  “relaxation  period.” 

3.  In  a  very  large  group  of  skilled  movements  the  moving 
member  meets  an  obstacle,  a  block  which  stops  the  movement 
without  further  muscular  activity;  whereupon  in  most  cases  the 
antagonistic  muscles  presently  contract  and  return  the  moving 
member  to  the  initial  position.  At  medium  speeds  the  block  may 
be  said  to  truncate  a  complete  movement  which  would  swing  to 
a  later  termination  coming  to  a  stop  with  the  contraction  of  the 
antagonistic  muscle  group;  instead  there  is  a  period  of  rest  at 
the  block  during  which  the  antagonistic  contraction  takes  place. 
As  a  repeated  movement  to  a  block  approaches  maximum  speed, 
the  pause  grows  less  and  less;  finally  the  block  becomes  a  mere 
limit,  the  angle  of  reverse  becomes  sharp  and  the  form  of  the 
movement  has  become  of  the  self-limiting  type.  Slow  movements 
may  rest  at  the  block  and  perhaps  exert  some  pressure  on  the 
block;  but  for  the  highest  speed  there  must  be  no  pressure  what¬ 
ever  on  the  block. 

Many  of  the  skilled  movements  of  musical  performance  are 
against  a  block;  piano  and  organ  playing,  fingering  of  strings  and 
wood  wind  and  the  brass.  In  piano  playing  rapid  octaves  if 
played  properly  will  actually  exert  very  little  pressure  on  the  pad 
beneath  the  keys.  In  typing  and  adding  machine  work  also  keys 
are  pressed  down  through  slight  resistance  to  a  definite  block. 
Sometimes  the  blow  is  delivered  to  a  resisting  surface  as  in  the 
various  movements  of  locomotion  and  in  many  of  the  consonant 

22  Ub.  Muskelzustande,  Zschr.  f.  Ps.  un.  d.  S.  31,  1.  32>  377- 


32 


R.  H.  STETSON  AND  JAMES  A.  MC  DILL 


strokes  of  speech.  Sometimes  the  external  resistance  is  elastic 
although  powerful  enough  to  check,  and  even  to  reverse  the 
movement ;  leaping  from  a  spring  board,  dancing  on  a  tight  rope, 
and  beating  the  various  drums  are  terminations  of  this  type. 

Blocked  movements,  movements  with  and  without  resistance, 
and  self-limiting  movements  frequently  occur  side  by  side  and 
are  nicely  organized  as  in  the  work  of  an  orchestra.  The  delicacy 
of  expression  and  celerity  possible  in  methods  of  execution  as 
different  as  those  of  the  piano,  violin,  harp,  and  voice  show  that 
there  may  be  a  remarkable  control  of  any  of  these  forms  of  ter¬ 
mination  of  the  skilled  movement. 

Experimental  Results. 

It  is  easy  to  show  that  the  nature  of  a  movement  is  not  affected 
by  the  fact  that  it  meets  increased  tension  during  a  part  of  its 
extent,  nor  by  the  fact  that  it  comes  up  against  a  complete  block. 
If  the  increased  tension  is  small  as  compared  with  the  weight 
of  the  moving  member,  there  is  no  change  in  the  curve  repre¬ 
senting  the  movement  and  it  sweeps  to  the  end  without  perceptible 
change.  The  muscular  contractions  for  stopping  a  self-limiting 
movement  and  for  returning  the  member  if  the  movement  is  re¬ 
peated  are  adjusted  to  the  external  tension;  the  form  of  the 
movement  is  in  nowise  affected. 

Figure  i  shows  a  movement  of  the  hand  and  arm  making 
an  excursion  of  150-250  mm.  During  the  lower  50  mm.  of  the 
free  excursion  the  hand  strikes  a  platform  of  small  mass  sus¬ 
pended  by  elastic  bands  which  give  a  tension  increasing  to  150  g. 


MECHANISM  OF  THE  DIFFERENT  TYPES 


33 


at  end  of  stroke.  There  is  no  indication  of  a  change  in  the  move¬ 
ment  when  the  hand  comes  in  contact  with  the  platform. 

Subject  blindfolded.  Platform  raised  and  lowered  rapidly 
through  60-70  mm.  Tension  350  g.  Points  at  which  platform 
is  raised-and-lowered  are  marked 


Duration  of  platform  movement,  sec.  .27 

.27 

.22 

.22 

.26 

.22 

.20 

•23 

•23 

•25 

.21 

.19 

.19 

.19 

.20 

.20 

.l8 

.19 

.23 

.24 

.21 

.21 

.21 

.23 

.22 

.21 

.24 

.24 

•17 

.22 

.27 

.28 

.l8 

.26 

30 

•25 

•23 

.26 


Extent  of  platform  movement,  mm.  46 

52* 

4i 

41 

51* 

41 

36 

47 

50* 

46 

36 

4i 

44 

41 
50* 

42 
34 

43 

49 
53* 
40 

36 
40 

56* 

43 

38 

50 
50* 

27 
38 

53 

48* 

28 
46 
65* 

38 

29 

37 


34 


R.  H.  STETSON  AND  JAMES  A.  MC  DILL 


Here  the  change  of  level  of  the  platform  has  been  made  rapidly 
enough  so  that  there  is  no  readjustment.  The  movement  dips 
into  the  platform  tension  and  goes  deeper  when  the  platform  is 

Duration  of  platform  movement,  sec.  .31  Extent  of  platform  movement  55 


.29 

51* 

.27 

42 

.27 

46 

.26 

40 

.26 

40 

.26 

35 

.26 

3i 

.31 

44 

.37 

58* 

.36 

46 

•30 

47 

.22 

32 

.18 

15 

.20 

31 

.27 

43 

•25 

48 

.28 

55* 

.26 

53 

.27 

5i 

.22 

45 

•30 

56 

.27 

55 

.27 

5i* 

.27 

55 

.24 

46 

.23 

49 

.24 

45 

Change  of  platform  level 

no  mm. 

23 

40 

.22 

40 

.24 

43 

.24 

45 

•23 

43 

.23 

40 

•25 

51* 

.22 

42 

.23 

39 

.19 

36 

.22 

41 

.25 

43 

•23 

37 

MECHANISM  OF  THE  DIFFERENT  TYPES 


35 


raised  and  comes  back  immediately  to  the  original  movement 
form  when  the  platform  is  lowered  to  the  normal  position.  The 
duration  and  extent  records  show  that  roughly  the  same  speed  is 
maintained  throughout. 

Subject  blindfolded,  makes  free  strokes  which  carry  down 
the  elastically  suspended  platform.  The  level  of  the  platform  is 
raised  and  lowered  slowly;  the  points  where  platform  is  at  maxi¬ 
mum  height  are  marked  Change  of  level  60-70  mm.  Ten¬ 

sion  350  g. 

Where  the  changes  of  level  are  made  gradually  the  tendency  to 
readjust  is  apparent;  the  movement  is  adjusted  by  the  preceding 
movement  sensations,  not  by  the  sensations  from  the  movement 
occurring.  There  are  many  illustrations  of  this  adjustment  in 
ordinary  life :  adjusting  to  the  dimensions  of  the  steps  as  one 
climbs  a  staircase;  adjusting  to  the  touch  of  a  strange  piano  or 
typewriter:  adjusting  to  a  novel  height  of  heel  in  walking,  etc. 
Some  eighteen  series  of  records  of  this  sort  were  taken  at  various 
speeds  of  ballistic  movement;  they  all  show  the  same  facts  as 
those  given  above.  The  records  are  from  but  a  single  subject, 
however,  and  need  corroboration. 


When  the  movement  plays  against  a  block,  a  very  common 
form  of  rapid  stroke,  if  the  movement  is  slow,  the  member  rests 
at  the  block  and  the  curve  looks  precisely  as  if  a  longer  self- 
limiting  movement  had  been  truncated  by  the  block.  Series  1 ) 
if  completed  would  have  been  60-70  mm.  in  length.  The  momen- 


36 


R.  H.  STETSON  AND  JAMES  A.  MC  DILL 


turn  and  possibly  some  contraction  of  flexor  muscles  is  expended 
at  this  block  level  and  the  extensor  contraction  which  is  to  raise 
the  arm  and  hand  develops  during  this  period  of  rest. 

If  the  speed  of  the  movement  to  the  block  is  increased  to  1.4 
per  sec.  the  form  of  the  movement  changes  and  the  pointed  end 
of  the  movement  occurs  at  the  block,  Series  2)  ;  there  is  no  longer 
a  period  of  rest  at  the  block.  Very  little  energy  is  expended  on 
the  block;  the  momentum  developed  in  the  moving  member  is 
quickly  neutralized  by  the  extensor  muscles  and  the  moving 
member  is  thrown  lightly  back  from  the  block  level. 

^47  yr-ry  y  \r—\r , 

*  V  v  v  1/  yzrxu. 

^ .. .. 

Fig.  3. 

If  the  distance  from  the  normal  level  of  the  platform  to  the 
block  is  small,  5-15  mm.,  e.g.,  the  tendency  to  rest  at  the  block  is 
more  pronounced  and  the  pause  at  the  block  is  apparent  in  Fig.  3 
in  1)  .6  per  sec.,  M.M  36,  in  2)  1.8  per  sec.  M.M  108,  and  in  3) 
2.1  per  sec.  M.M  126.  But  in  4)  at  the  speed  of  4  per  sec.  M.M 
240  the  pause  has  disappeared  and  the  path  of  the  movement 
barely  touches  the  block.  Cf.23 

A  number  of  records  of  this  type  from  the  one  subject  are  all 
consistent  but  there  is  need  of  records  from  more  subjects. 

Bearing  on  the  Type  of  Movement  on  the  Process  of  Learning 

1.  The  “form”  of  the  movement: 

Wherever  rapid  and  repeated  movements  are  important  as  in 
musical  technic,  use  of  keyboard  machines,  telegraphy,  writing, 

23  Mot.  Theory  of  Rh.  and  Discrete  Sue.  Psy.  Mon.  Sup.  12,  ’05,  263. 


MECHANISM  OF  THE  DIFFERENT  TYPES 


37 


and  shorthand,  the  type  of  movement  has  been  recognized  as  very 
important.  Keyboard  work  has  been  completely  reorganized  on 
the  basis  of  the  “loose”  movement  which  is  simply  a  carefully 
maintained  ballistic  movement  of  finger,  hand,  and  forearm  with 
the  use  of  weight  of  momentum  as  far  as  possible.  Telegraphic 
keys  have  been  modified  and  the  technic  emphasized  because  both 
speed  and  freedom  from  occupational  neurosis  depend  on  obtain¬ 
ing  the  ballistic  form.  In  writing  it  happens  that  a  remarkable 
piece  of  early  work  was  done  in  the  development  of  the  ballistic 
technic.  Spencer  not  only  developed  remarkably  good  cursive 
forms  of  the  written  letter,  but  he  also  achieved  a  technic  of  the 
writing  movement  which  gave  great  speed  and  endurance  with 
beauty  of  form.  There  are  careful  directions  for  the  “muscular 
movement,”  in  which  the  forearm  slides  freely  and  ballistically 
about  on  the  mass  of  flexor  muscles  and  tight,  cramping  movements 
of  the  finger  and  hand  are  avoided.  Chinese  and  Japanese  brush 
writing  and  drawing  have  also  achieved  the  fast,  free  stroke. 
The  line  of  Japanese  painting  is  a  free  hand  and  free  arm  drawing 
with  the  swift  certainty  of  the  skilled  ballistic  movement.  The 
bad  line  in  drawing  is  the  result  of  “controlled”  movements.  In 
many  of  these  skilled  movements,  piano  playing,  telegraphy, 
Spencerian  writing  for  example,  the  form  of  the  movement  is 
more  or  less  conscious  and  the  method  of  training  for  getting  the 
technic  is  fairly  adequate.  But  in  many  skilled  processes  the 
ballistic  form  of  the  movement  is  the  result  of  chance  or  the 
movement  goes  on  hampered  by  opposing  tensions. 

2.  The  development  of  speed;  transition  from  the  slow  to 
the  ballistic  movement;  problem  of  the  plateau  of  the  learning 
curve. 

A  few  skilled  movements  like  diving  or  serving  at  tennis  must 
be  practiced  at  speed  from  the  start,  but  most  of  the  complicated 
skilled  movements  are  begun  slowly  and  gradually  increased  in 
speed.  Mistakes  in  the  precise  path  of  the  movement  are  usually 
counted  lapses  in  “accuracy.”  These  are  kept  to  a  minimum  and 
constantly  corrected  while  the  movement  is  repeated  at  higher  and 
higher  speed.  This  is  the  great  feature  of  the  process  called 


38 


R.  H.  STETSON  AND  JAMES  A.  MC  DILL 


training  or  “development  of  skill.”  It  is  usually  assumed  that 
the  movement  is  being  stereotyped,  ground  in  by  repetition,  and 
that  the  increase  of  speed  is  merely  a  matter  of  gradually  in¬ 
creasing  the  tempo  while  the  movement  remains  the  same.  First 
get  the  path  of  the  movement  accurately  and  then  gradually  speed 
up  until  you  reach  the  normal  tempo.  On  the  assumption  that  it 
is  one  and  the  same  movement  process  at  the  different  speeds  it 
has  always  been  something  of  a  puzzle  that  the  learning  curve 
fails  to  show  a  regular  increase  in  speed  Instead  of  a  gradual 
and  regular  increase,  the  curve  shows  rather  rapid  gains  at  points 
with  long  periods  of  practice  between  during  which  there  is  no 
apparent  gain  at  all.  There  are  various  explanations :  periods  of 
assimilation  in  which  recent  gains  are  being  consolidated;  com¬ 
pensation  between  improvement  and  fatigue,  etc.  The  funda¬ 
mental  fact  is  that  the  movement  itself  changes  with  the  increase 
in  speed;  it  is  not  the  same  movement  throughout  training.  Be¬ 
ginning  as  a  slow  process  composed  of  many  movement  elements 
and  with  frequent  pauses,  the  increasing  speed  means  that  fewer 
movement  elements  must  take  the  place  of  the  many.  The  path 
of  the  movement  has  not  changed  but  a  process  which  included 
twenty  movements,  and  might  be  stopped  at  twenty  different 
places  and  may  have  paused  at  many  of  them,  is  now  reduced  to 
fifteen,  to  seven,  to  three.  In  reality  passing  from  slow  to  rapid 
is  a  matter  of  substituting  a  single  movement  for  several  move¬ 
ments  over  the  same  path.  Nothing  else  can  happen;  if  about  ten 
movement  elements  per  second  is  the  maximum,  a  given  move¬ 
ment  beginning  with  ten  movement  elements  must  be  reduced  to 
less  than  ten  movement  elements  when  the  speed  exceeds  one  per 
second.  If  the  given  movement  takes  place  at  the  rate  of  two 
per  second  the  original  ten  movement  elements  must  be  reduced 
to  at  most  five.  When  the  beginner  prints  a  character  at  the  type¬ 
writer  he  first  puts  his  finger  on  the  key,  and  then  presses  it  down ; 
later  the  placing  and  striking  must  become  one  stroke.  In  many 
cases  different  groups  of  muscles  are  employed  for  the  slow  and 
the  rapid  movements ;  the  movements  are  different  in  every  sense, 
they  consist  of  different  numbers  of  grouped  movement  elements 


MECHANISM  OF  THE  DIFFERENT  TYPES 


39 


executed  by  different  muscle  groups.  And  this  fact  must  have  an 
important  influence  on  the  learning  curve.  When  the  “form”  of 
the  movement  is  stable,  when  the  number  and  grouping  of  the 
movement  elements  is  no  longer  changing,  the  increase  in  speed 
is  very  slow  indeed  but  is  gradual — as  at  the  end  of  training 
when  the  subject  comes  very  slowly  to  his  maximum  efficiency. 
It  is  perhaps  due  to  gradual  nutrition  changes  (“development” 
of  muscles)  and  to  the  refinement  of  the  cues  and  adjustments 
which  direct  the  movement.  But  during  a  large  part  of  the  ob¬ 
vious  and  relatively  rapid  improvement,  the  “form”  of  the  move¬ 
ment,  the  actual  movement-process  is  subject  to  change.  When 
a  new  and  more  condensed  group  of  movement  elements  is  sub¬ 
stituted  for  the  more  detailed  and  segmented  group  there  is  a 
very  rapid  increase  in  speed.  But  these  new  “forms”  of  move¬ 
ment,  these  new  combinations  of  the  individual  units  are  blun¬ 
dered  into.  During  the  plateau  the  subject  is  repeating  the  move¬ 
ment  verbatim  until  chance  gives  a  better  way  and  he  falls  into 
a  better  “form.”  “Plunging”  at  the  expense  of  mistakes  has  its 
advantages  for  thereby  the  subject  comes  to  new  and  more  rapid 
“forms”  for  covering  the  same  movement  path.  The  advantage 
of  ensemble  playing  for  the  beginner  in  music  is  that  it  forces 
him  to  try  things  at  a  speed  which  compels  new  combinations, 
with  approximate  accuracy  in  the  main  movements  at  least. 
Mere  repetition  does  not  constitute  fruitful  practice;  changes  in 
the  type  of  movement  used  are  essential. 

Summary 

Movements  may  be  classed  as  i.  movement  of  holding  still 
— fixation,  2.  slow  movement,  3.  fast  movements,  A.  with  ten¬ 
sion,  B.  Ballistic.  The  difference  between  these  classes  is  due 
to  the  number  of  movement  elements  in  each  type  of  movement. 
The  movement  elements  are  equivalent  to  the  tremor  undulations. 
In  fixation  a  number  of  muscle  groups  contract  against  each  other 
and  the  tremor  is  the  only  change  of  position.  In  the  slow  move¬ 
ment  there  are  a  large  number  of  movement  elements  per  unit 
of  length  and  the  movement  can  apparently  be  changed  at  any 


40 


R.  H.  STETSON  AND  JAMES  A.  MC  DILL 


point  in  its  course;  it  is  “controlled.”  In  the  fast  movement  there 
are  few  elements,  only  a  few  changes  are  possible;  at  the  maximum 
rate  when  each  stroke  consists  of  but  one  element,  no  change 
during  the  course  of  the  movement  is  possible.  In  the  fast  move¬ 
ment  under  tension  the  movement  of  translation  is  superimposed 
on  a  movement  of  fixation.  In  the  ballistic  movement  there  is 
a  minimum  muscle  contraction  during  the  flight  of  the  move¬ 
ment.  A  single  impulse  of  the  positive  muscle  group  starts  a 
very  rapid  movement;  during  the  earlier  course  of  the  movement 
this  impulse  ceases  and  the  moving  member  swings  free  to  the 
termination  of  the  movement.  Such  a  ballistic  movement  will 
have  a  duration  independent  of  the  extent  of  the  stroke;  long  or 
short,  the  movement  can  be  repeated  at  a  maximum  rate  which 
approaches  the  tremor  frequency  of  the  groups  of  muscles  in¬ 
volved. 

There  are  three  common  forms  for  the  termination  of  a  move¬ 
ment:  i.  the  moving  member  swings  loose  and  is  arrested  by 
ligaments  and  passive  muscles,  2.  the  moving  member  is  ar¬ 
rested  by  the  contraction  of  the  antagonistic  muscle  group,  3.  the 
moving  member  is  arrested  by  an  obstacle.  The  first  form  is  less 
usual;  the  second  is  the  common  type  or  “free”  or  self-limiting 
movement;  the  third  is  very  common  in  all  sorts  of  rapid  ma¬ 
nipulation  of  mechanical  apparatus.  When  the  movement  ter¬ 
minating  at  an  obstacle  occurs  at  maximum  speed  it  tends  to  be¬ 
come  self-limiting. 

In  training  the  type  of  the  movement  changes  from  slow  to 
ballistic  although  the  path  of  the  movement  does  not  change. 
Plateaux  in  the  learning  curve  are  due  to  periods  in  which  the 
movement  is  repeated  without  change  of  type  and  therefore  at 
the  same  speed.  Devices  in  training  are  important  which  lead 
to  the  development  of  new  “forms”  of  the  movement. 


MEASUREMENTS  OF  RHYTHMIC  UNIT-GROUPS  AT 

DIFFERENT  TEMPOS 

R.  H.  Stetson  and  T.  E.  Tuthill 

The  fundamental  groups  of  a  rhythmic  series  consist  of  ac¬ 
cented  and  unaccented  beats.  In  musical  notation  it  has  been 
customary  to  give  these  beats  a  strictly  quantitative  expression. 
It  is  assumed  in  musical  instruction  and  occasionally  in  psycho¬ 
logical  theory  that  the  quantitative  temporal  relations  are  an 
essential  factor  in  the  unit-group. 

The  iamb  or  “dotted-eighth-sixteenth”  figure  was  chosen  as 
one  of  the  simplest  and  most  obvious  unit-groups  with  a  pro¬ 
nounced  difference  in  the  length  of  the  elements  and  a  very 
definite  accent.  The  question  was  raised :  Is  the  musical  iamb 
actually  played  in  a  fixed  temporal  form  as  indicated  by  the  mu¬ 
sical  notation?  The  commonest  form  of  the  iamb  was  chosen 
and  a  half  dozen  trained  musicians  were  asked  to  play  this 
rhythm  at  different  tempos;  the  records  were  carefully  measured. 
The  form  that  the  musicians  were  asked  to  play  was  always  a 
simple  phrase : 


The  rhythms  were  tapped  on  a  key  which  gave  a  clear  sound  like 
that  of  the  Vergil  clavier  with  which  all  the  subjects  were  fa¬ 
miliar.  The  beats  were  recorded  on  a  carefully  controlled  kymo¬ 
graph  drum.  The  subjects  were  all  accustomed  to  ensemble 
playing,  were  considered  accurate  in  rhythm,  and  were  all  aware 
that  the  “accuracy”  of  their  rhythms  was  to  be  tested.  They  did 
their  best  to  make  the  form  correct  as  they  conceived  it. 

The  following  tables  show  a  sample  of  the  actual  measurements 
in  one  case  and  of  the  computed  averages  and  mean  variations  for 
the  series  of  readings  of  the  records  of  each  of  the  six  subjects. 

Records  of  doublets  and  triplets  (trochees  and  dactyls)  have 
been  added  for  comparison. 


41 


42 


R.  H.  STETSON  AND  T.  E.  TUTH1LL 


TABLE  I 

Subject  W. 

Iambs 

Readings  in  tenths  of  millimeter  from  kymograph  drum. 


Metronome  rate  50 


50 

80 

100 

120 

js 

Is  1 

*  N 

1 

0* 

e  i 

J.  J 

S  d. 

i 

J'  4. 

173 

561 

315 

840 

1 37 

410 

170 

706 

168 

526 

285 

755 

125 

370 

167 

683 

306 

764 

132 

4i5 

172 

682 

168 

506 

292 

765 

120 

405 

172 

6 77 

175 

490 

292 

700 

127 

377 

170 

631 

307 

663 

120 

416 

160 

630 

251 

830 

278 

674 

148 

681 

262 

830 

280 

666 

147 

460 

158 

690 

242 

796 

234 

570 

148 

442 

170 

665 

240 

640 

136 

477 

147 

676 

213 

702 

233 

617 

152 

476 

145 

650 

240 

762 

237 

616 

170 

485 

160 

668 

240 

730 

230 

634 

167 

475 

154 

650 

160 

496 

152 

640 

315 

849 

158 

650 

313 

810 

175 

450 

160 

663 

321 

807 

503 

184 

170 

650 

182 

488 

196 

503 

170 

5io 

of  the 

short 

note  to 

the  long 

note : 

100 


120 


M.M.  50  80 

Theoretical  ratio,  assuming  that  the  iamb  is  a  quantitative  expression 


250  750 

250750 

250  750 

250750 

W.  240  760 

mv  30  284716  mv  30 

252  748  1 

mv  10 

190:810 

mv  10 

Subject  W 

M.M.  40 

80 

120 

160 

180 

180  400 

135  400 

160 

400 

145 

280 

140 

235 

180  500 

170  390 

165 

400 

140 

260 

130 

220 

195  5io 

165  520 

170 

420 

130 

290 

120 

215 

180  470 

200  500 

170 

420 

135 

300 

120 

215 

190  510 

145 

225 

Averages : 

Theoret. 

250750 

250750 

250  750 

250750 

250  750 

W.  275  725  mv 

7  268  732  mv  27 

290 

710  mv  6 

323  1677  mv  13 

366  1634  mv 

MEASUREMENTS  OF  RHYTHMIC  UNIT-GROUPS 


43 


At  the  slower  tempos  M.M.  50  and  80  many  of  the  individual 
figures  are  far  enough  from  the  theoretical  ratio  so  that  the  dif¬ 
ference  could  easily  be  detected  by  the  ear.  The  average  values 
are  not  far  enough  from  the  theoretical  ratio  so  that  the  difference 
could  be  detected  by  the  ear.  The  average  at  M.M.  120  is  far 
enough  from  the  theoretical  ratio  to  be  at  the  threshold  of  dis¬ 
crimination,  40-66  sigma.  It  is  to  be  noted  that  at  none  of  the 
tempos  do  the  values  vary  about  the  theoretical  ratio  as  a  norm. 

In  the  second  series  from  the  subject  W.  it  is  to  be  noted  that 
the  forms  do  not  agree  with  other  records  from  the  same  sub¬ 
ject,  save  in  having  the  short  note  in  general  longer  than  the 
theoretical  value. 


TABLE  II 

Subject  M 

Averages  of  readings  expressed  as  ratios 


M.M.  40 

M.  346:654  av.  14  rdgs  mv  59 
Theoret. 

250  750 

M.M.  100 

M.  294:706  av.  1 7  rdgs,  mv  12 
M.M.  140 

M.  285:715  av.  14  rdgs,  mv  11 


80 

312:688  av.  11  rdgs,  mv  12. 

250  750 

120 

267723  av.  15  rdgs,  mv  13 
180 

326:674  av.  20  rdgs,  mv  13. 


TABLE  III 

Subject  D 

Iamb 

Averages  of  readings  expressed  as  ratios 


M.M.  40 

80 

D.  331  =669  av.  7  rdgs, 

mv  16 

366  :634 

av.  9  rdgs,  mv 

15 

283717  5 

4 

354  =646 

8 

14 

Theoret. 

250:750 

250  750 

M.M.  120 

160 

D.  315:685  av.  8  rdgs, 

mv  6 

316  :684 

av.  7  rdgs,  mv 

9 

335 :665  5 

316  :684 

7 

13 

Theoret. 

250  750 

250  750 

44 


R.  H.  STETSON  AND  T.  E.  TUTHILL 


In  Table  II  the  individual  unit-groups  show  values  at  all  tempos 
which  could  easily  be  discriminated  by  the  ear  from  the  theoretical 
ratio.  In  the  case  of  M.M.  40  and  80  the  average  of  the  readings 
is  so  unlike  the  theoretical  ratio  that  the  difference  would  be  ob¬ 
vious  to  the  ear.  As  often,  the  mean  variation  shows  greater 
irregularity  at  the  slow  tempos. 

The  divergencies  from  the  theoretical  ratio  at  the  lower  tempos 
as  shown  in  Table  III  are  pronounced  and  would  be  obvious  to 
the  ear. 

TABLE  IV 

Subject  H 
Iamb 

Averages  of  readings  expressed  as  ratios 


M.M.  40 

80 

H.  400:600  av. 

10  rdgs,  mv 

24 

393  :6o7  av.  8  rdgs,  mv  8 

370 1630 

8 

22 

373 :627  10 

26 

362 1638 

10 

4 

353 :647  8 

14 

Theoret. 

250  750 

250  750 

M.M.  120 

160 

H.  364:636  av. 

11  rdgs,  mv  47 

366:634  av.  10  rdgs,  mv  26 

335  :665 

10 

1 7 

330 :670  6 

10 

330 :6;o 

7 

16 

354:646  7 

7 

Theoret. 

250750 

250  750 

M.M.  200 

H.  354 :646  av. 

9  rdgs  18 

360:640  av. 

14  rdgs  14 

344:656  av. 

7  rdgs  34 

Theoret. 


250  750 

At  all  tempos  in  all  three  records  in  Table  IV,  the  short  note 
of  the  unit-group  is  much  longer  than  the  theoretical  value,  and 
as  a  rule  is  longer  than  that  given  by  other  subjects.  In  nearly 
every  case  the  individual  unit-group  as  played  could  be  discrimi¬ 
nated  by  ear  from  a  figure  played  with  the  theoretical  values. 

The  type  used  by  the  subject  is  very  definite;  there  is  little 
variation  at  any  tempo. 


MEASUREMENTS  OF  RHYTHMIC  UNIT-GROUPS 


45 


TABLE  V 

Subject  P 

Iamb 

Averages  of  readings  expressed  as  ratios 


M.M.  40 

80 

P.  325  :675  av. 

4  rdgs.  mv  13 

318  1682 

av.  8  rdgs, 

mv  9 

3d2  :675 

4  10 

240  760 

8 

14 

263  737 

4  8 

251  749 

5 

12 

348  =652 

5  7 

222  778 

3 

0 

Theoret. 

250750 

250  750 

M.M.  120 

160 

P.  283  717  av. 

4  rdgs,  mv  0 

362  :63s 

av.  4  rdgs, 

mv  33 

303  :697 

6  10 

299 :7c 1 

6 

18 

308  1692 

5  6 

325  :675 

5 

30 

246  754 

4  0 

276  724 

3 

0 

Theoret. 

250  750 

250:750 

The  number  of  readings  recorded  in  Table  V  is  rather  small. 


TABLE  VI 


Subject  S 

Iamb 

Averages  of  readings  expressed  as 
M.M.  40 

S.  262  738  av.  6  rdgs,  mv  18 
Theoret. 

250:750 

M.M.  100 

S.  366:634  av.  10  rdgs,  mv  18 
Theoret. 

250  750 


ratios 

80 

352:648  av.  11  rdgs,  mv  10 
250:750 

120 

325  :675  av.  12  r<fgs,  mv  6 
250  750 


M.M.  140  160 

S  380:620  av.  12  rdgs,  mv.  20  400:600  av.  12  rdgs,  mv.  24 

Theoret. 

250  750  250  750 

Iamb  at  tempos  which  increase  by  small  intervals.  Mean 
variation  as  usual. 


46 


R.  H.  STETSON  AND  T.  E.  TUTHILL 


M.M.  40 

50 

60 

72 

359:641  av.  10  rdgs 

249751  av. 

10  rdgs 

360  -.640  10 

409:591  av.  10  rdgs 

457 :543 

10 

375:625  av. 

10  rdgs 

317:683  10 

348 :652  10 

361 :639 

10 

409 :59i 

10 

Theoret. 

355  :645 

10 

332 :668 

10 

250  750 

250  750 

250  750 

250:750 

M.M.  84 

96 

108 

112 

351 :649  av.  10 

323:677  av.  10  rdgs 

409,591  av. 

10  rdgs 

364:656  av. 

10  rdgs 

336 :664  10 

390:610  10 

376 :624 

10 

Theoret. 

388:612  10 

350 1650 

10 

250  750 

250  750 

250  750 

M.M.  126  140 

340:660  av.  10  rdgs  348:652  av.  10  rdgs 

250:750  250:750 

In  the  records  of  Table  VI  the  short  note  of  the  unit-group  is 
longer  than  the  theoretical  value ;  this  is  in  accord  with  the  records 
of  other  subjects.  In  the  case  of  the  slower  tempos  and  occasion¬ 
ally  at  the  higher  tempos,  the  difference  is  large  enough  to  be 
easily  recognized  by  the  ear. 

It  is  apparent  that  the  type  of  iamb  may  change,  not  only 
from  subject  to  subject,  but  from  time  to  time  with  the  same 
subject;  though  the  coordination  is  maintained  when  once  estab¬ 
lished.  For  example  in  Table  VI  at  M.M.  40,  the  type  260:740 
is  decidedly  different  from  the  type  360:640.  So  also  at  M.M. 
60,  type  250:750,  type  460:540,  and  type  350:650  are  decidedly 
different.  The  variation  within  each  of  such  a  series  is  slight, 
showing  that  the  averages  are  not  accidental. 

Table  VII  shows  the  usual  variations.  M.M.  40  there  are  two 
types  of  iamb  apparent,  type  240:760,  and  type  c. 340:660.  All 
the  other  figures  £re  fairly  uniform.  With  the  exception  of  the 
single  case  just  mentioned  at  M.M.  40,  the  averages  show  a  type 
in  which  the  short  note  is  longer  than  the  theoretical  value. 


MEASUREMENTS  OF  RHYTHMIC  UNIT-GROUPS 


47 


TABLE  VII 


Subject  T 

Iamb 

Average  of  readings  expressed  as  ratios 


M.M.  40  60 

243  757  av.  11  rdgs,  mv.  14  340:660  av. 
358 1642  10 

369:581  10 

300 1700  6 

329:671  10 

343 :657  7 

313:687  9 

331 :66g  10 

Theoret. 

250  750 


80 

13  rdgs,  mv.  27  248:752  av.  13  rdgs,  mv.  12 

242  758  10 

299  701  10 

313:687  10 

2  76  724  8 

357 :643  9 


250750 


M.M.  100 

120 

272728  av.  13  rdgs,  mv.  9 

300700  av. 

11  rdgs,  mv.  6 

283:711 

10 

317:683 

10 

290:710 

10 

284716 

10 

287713 

11 

320 :68o 

10 

Theoret 

309:691 

9 

250  750 

250  750 

M.M.  140 

160 

342:658  av.  12  rdgs,  mv.  27 

294  706 

av.  10  rdgs,  mv.  18 

314:686 

10 

347  :653 

10 

352 :648 

10 

385 :6i5 

10 

331  -.669 

10 

Theoret. 

327 :673 

10 

250  750 

250  750 

48 


R.  H.  STETSON  AND  T.  E.  TUTHILL 


TABLE 


Subject  H 

Trochee  doublet  (  " 

"1) 

1 

# 

j 

0 

> 

MM.  40 

80 

513:487  av.  8  rdgs,  mv.  15 

525 

518:482  4 

502 

Theoret 

500:500 

500 

M.M.  120 

160 

509:481  av.  11 

rdgs,  mv.  9 

440 

515:485  8 

505 

Theoret. 

500:500 

500: 

Subject  S 

Trochee,  doublet  (  1" 

1 

n> 

1 

# 

>■ 

M.M.  80 

100 

580:420  av.  16 

rdgs,  mv.  17 

540 

Theoret : 

500 :500 

500 

M.M.  120 

140 

509:491  av.  14 

rdgs 

515' 

Theoret 

500:500 

Subject  W 

Trochee,  doublet  (  j‘ 

“I) 

J 

1 

& 

M.M.  40 

80 

512:488  av.  5  rdgs,  mv  15 

507: 

Theoret. 

500:500 

500: 

M.M.  120 

140 

504:496  av.  16  rdgs 

529: 

VIII 

1475  av.  7  rdgs,  mv.  19 
1498  9 

:5°° 

200 

: 560  av.  10  rdgs  507  1493  av.  10  rdgs 
:495  9 

1500  500:500 

1460  av.  10  rdgs 

:50O 

1485  av.  14  rdgs 
500:500 

100 

493,  av.  8  rdgs,  mv.  20  515:485,  av.  14 

500  500:500 

471  av.  20  rdgs 


In  all  the  trochees  of  Table  VIII  the  accented  note  is  length¬ 
ened.  This  lengthening  of  the  accented  note  has  been  frequently 
reported.  The  doublet  does  not  vary  as  much  from  the  theoretical 


MEASUREMENTS  OF  RHYTHMIC  UNIT-GROUPS 


49 


value  as  does  the  iamb.  The  variation  from  tempo  to  tempo  and 
from  sitting  to  sitting  is  probably  due  to  the  amount  of  accent 
thrown  on  the  first  note  of  the  doublet;  it  is  well  known  that  an 
increase  in  the  accent  increases  the  length  of  the  accented  note. 


TABLE  IX 


Subject  S 


Dactyl,  triplet 


rr 


©  ©  © 

3 


) 


M.M.  40 

478:262:259  av.  7  rdgs,  mv.  15 
Theoret. 


333  :333  :333 
M.M.  100 

343:326:329  av.  7  rdgs,  mv.  14 


80 

388:315:296  av.  7  rdgs,  mv.  12 

333  :333  :333 
120 

343:328:329  av.  7  rdgs,  mv.  16 


Theoret. 

333  :333  '333  333  1333  :333 

M.M.  140 

345:334:321  av.  7  rdgs,  mv  8 
Theoret. 

333  :333  :333 


Subject  W . 

M.M.  40 

374:359:269  av.  4  rdgs,  mv.  6 
Theoret. 

333  -333 : 333 
M.M.  100 

336:328:335  av.  5  rdgs,  mv.  n 
Theoret. 

333  '-333 : 333 

M.M.  140 

352:318:330  av.  4  rdgs,  mv.  12 
Theoret. 

333  :333  :333 


80 

344:335:321  av.  7  rdgs,  mv.  5 

333  :333 : 333 
120 

341:333:326  av.  14  rdgs,  mv.  11 
333  -333 : 333 


Like  the  trochees,  these  dactyls  of  Table  IX  show  the  lengthen¬ 
ing  of  the  accented  note.  It  is  much  more  pronounced  in  some 
cases.  The  type  is  fairly  well  maintained  in  a  given  trial,  as  the 
mean  variations  show. 


50 


R.  H.  STETSON  AND  T.  E.  TUTHILL 


Discussion  of  Results 

It  is  rare  indeed  that  the  actual  temporal  relations  of  a  musical 
iamb  of  the  dotted-eighth-sixteenth  form  correspond  at  any 
tempo  to  the  ‘'theoretical  value”  of  the  notation.  Not  only  do 
the  individual  unit-groups  differ  from  this  theoretical  ratio,  but 
the  averages  do  not  vary  about  this  ratio  as  a  norm.  Only  six 
series,  involving  sixty-one  readings,  out  of  seventy  one  series, 
involving  one  thousand  fifty-two  readings,  show  values  near  the 
theoretical  value.  These  series  whose  averages  are  near  the 
supposed  norm  are  not  to  be  found  at  any  particular  tempo,  nor 
with  any  particular  subject;  they  are  infrequent  and  accidental. 

In  general  the  unaccented  note  of  the  iamb  is  decidedly  longer 
than  the  theoretical  value  at  all  tempos  and  with  all  subjects.  The 
type  of  the  unit-group  at  a  given  tempo  for  a  given  sitting  is 
fairly  constant,  as  the  mean  variations  show;  but  the  type  varies 
widely  not  only  from  subject  to  subject  and  from  tempo  to  tempo, 
but  also  from  sitting  to  sitting  at  the  same  tempo  with  the  same 
subject. 

The  records  of  triplets  and  doublets  show  the  usual  lengthening 
of  the  accented  note,  when  compared  with  the  theoretical  value. 
In  the  case  of  the  iamb  however  the  “lengthening”  of  the  short 
unaccented  note  cannot  be  attributed  to  accent. 

The  results  tend  to  show  that  the  groupings  of  the  fundamental 
rhythmic  unit-groups  are  not  a  matter  of  quantitative  time  di¬ 
vision;  the  sense  of  rhythm  cannot  be  explained  in  terms  of 
judgment  of  time  intervals.  Professionally  trained  subjects  are 
unable  to  achieve  the  theoretical  ratios.  The  types  are  much  too 
variable ;  with  these  six  musicians  the  records  show  time  divisions 
for  the  dotted-eighth-sixteenth  unit-group  which  vary  all  the  way 
from  the  theoretical  ratio  i  13  through  1  :2  to  2  -.3  and  there  is  no 
preference  for  some  simple  ratio. 

On  the  other  hand,  the  grouping  is  not  the  random  placing  of 
some  short  before  a  long  so  that  “the  ‘attention’  subordinates  the 
minor  to  the  major  element.”  The  small  variations  show  a  pre¬ 
cise  movement  type  for  each  sitting.  Some  process  makes  the 
division  fairly  exact  for  each  sitting. 


MEASUREMENTS  OF  RHYTHMIC  UNIT-GROUPS 


5i 


The  conception  of  a  rhythmic  unit-group  as  an  organized 
group  of  movements  whose  conditions  are  muscular  comes  nearer 
to  fitting  the  facts.  It  is  quite  possible  to  establish  a  coordination 
involving  particular  muscles  and  a  particular  stress  on  the  ac¬ 
cented  beat  which  shall  give  precise  movements  during  a  single 
sitting.  Since  the  movements  are  precise  their  time  intervals  are 
also  fixed  and  regular.  Changes  of  stress  and  of  muscle  group 
alter  the  type  of  unit-group.  The  limits  of  the  variation  of  short 
and  long  in  the  musical  iamb  are  the  limits  of  the  possible  co¬ 
ordinations  which  give  a  satisfactory  grouping  of  a  light  short 
pulse  and  a  following  heavy  pulse  into  a  single  movement  cycle. 


THE  APPLICATION  OF  THE  BINET-SIMON  TESTS  TO 
GROUPS  OF  WHITE  AND  COLORED 
SCHOOL  CHILDREN* 

George  R.  Wells 

It  has  seemed  to  the  writer  that  Oberlin  offers  a  very  fine  op¬ 
portunity  to  test  the  relative  mental  abilities  of  white  and  colored 
children.  There  is  a  fairly  large  number  of  colored  children  in 
the  public  schools  of  Oberlin,  large  enough  to  give  some  signifi¬ 
cance  to  a  comparative  test.  The  not  unimportant  part  which 
Oberlin  as  a  community  and  as  a  college  has  historically  taken 
in  the  emancipation  propaganda  attracted  many  colored  residents 
both  before  and  after  the  war,  a  species  of  selection  probably 
operating  to  choose  the  more  intelligent  and  energetic  members 
of  the  race.  And  the  influences  which  attracted  them  were  more 
or  less  effective  to  make  the  negroes  welcome  when  they  settled 
here,  and  to  some  extent,  are  still  effective  in  the  same  way. 

It  has  come  about  that  at  the  present  time  colored  residents 
are  less  set  apart  from  white  people  than  in  most  communities. 
The  social  environments  of  the  two  races  are  not  as  different  as 
in  practically  all  southern  and  most  northern  towns.  The  mem¬ 
bers  of  both  races  attend  school,  church  and  college  on  exactly 
the  same  terms.  Of  course  this  does  not  mean  that  the  social 
environment  of  a  colored  family  is  identical  with  that  of  the  aver¬ 
age  white  family.  But  if  the  conditions  for  testing  racial  mental 
characteristics  are  not  entirely  free  from  the  disturbances  of  en¬ 
vironmental  variations,  they  are  perhaps  as  nearly  free  as  we  are 
apt  to  find  anywhere  in  the  country. 

During  the  spring  of  1914  an  investigation  was  made  of  the 
relative  mentality  of  the  white  and  colored  pupils  in  the  public 
schools  of  Oberlin.  In  this  investigation  the  writer  was  assisted 
by  a  group  of  his  students  from  the  Psychological  Laboratory  of 

*  The  above  article  was  written  in  1915. 


52 


APPLICATION  OF  THE  BINET -SIMON  TESTS 


53 


Oberlin  College  and  by  three  members  of  the  senior  class  of  the 
Oberlin  Kindergarten  Training  School,  to  all  of  whom  acknowl¬ 
edgment  is  hereby  made. 

The  tests  applied  were  the  ordinary  Binet-Simon  series.  The 
form  of  test  used  was  Huey's  edition  of  Goddard’s  revision  of  the 
191 1  scale,  as  listed  in  the  forms  published  by  Warwick  and  York. 
The  investigation  was  officially  recognized  by  Superintendent 
Rawdon  of  the  Oberlin  Public  School  system.  A  room  was  placed 
at  the  disposal  of  the  examiners  at  each  of  the  three  schools,  and 
the  pupils  were  sent  from  their  class  rooms  to  these  examining- 
rooms  one  by  one.  By  this  and  other  means  it  was  possible  to  make 
the  tests  with  very  little  distraction 

Several  problems  of  procedure  arose  early  in  the  investigation. 
The  period  of  testing  covered  several  weeks,  and,  in  spite  of 
directions  to  the  contrary,  there  is  reason  to  believe  that  there  was 
some  little  discussion  of  the  tests  among  the  pupils.  There  are 
two  possible  means  of  lessening,  though  not  of  eliminating,  the 
effect  of  such  discussion,  assuming  that  it  existed.  In  the  first 
place,  alternative  questions  could  be,  and  were,  used  to  some  ex¬ 
tent.  But  the  limit  of  this  method  was  soon  reached.  More  to 
the  point  was  the  carefully  carried  out  practice  of  having  the 
tests  on  whites  and  blacks  go  on  at  the  same  time.  White  and 
colored  children  were  examined  in  haphazard  order.  So  that  if 
any  effect  was  produced  by  the  conversation  among  the  children 
concerning  the  tests  there  is  no  reason  to  suppose  that  it  influenced 
one  race  more  than  another.  The  comparative  value  of  the  tests 
is  certainly  not  affected  by  this  influence. 

Again  it  was  found  early  in  the  tests  that  there  was  difficulty 
in  the  application  of  the  fifteen  year  old  test.  For  if  a  child 
passes  the  twelve  year  old  test  and  fails  in  the  fifteen  year  test 
there  is  some  room  for  doubt  as  to  how  he  should  be  classified. 
If  there  were  thirteen  or  fourteen  year  tests  the  child  might  pass 
one  or  both  of  them.  It  is  evident,  I  think,  that  mental  age  above 
twelve  years  can’t  be  measured  by  the  Binet-Simon  scale.  The 
following  rules  were  adhered  to  in  the  calculation  of  the  mental 
age  after  the  tests  has  been  administered. 


54 


GEORGE  R.  WELLS 


1.  All  tests  “over  fifteen”  were  entirely  neglected. 

2.  When  the  mental  age  of  any  child  proved  to  be  above 
twelve,  no  matter  what  his  actual  age,  the  card  record  of  that 
case  was  discarded,  and  that  record  does  not  enter  into  the  final 
results. 

3.  All  cases  of  over  twelve  years  actual  age  were  likewise 
neglected  unless  the  child  failed  in  either  the  twelve  year  or  in 
the  eleven  year  tests. 

4.  If  a  child  over  twelve  years  actual  age  failed  in  the  eleven 
or  in  the  twelve  year  tests,  the  fifteen  year  tests  were  given.  If 
successfully  passed  these  counted  as  one  additional  year,  or  re¬ 
spective  fraction  thereof.  But  if  the  addition  of  this  year  made 
the  mental  age  over  twelve  the  card  was  thrown  out  as  above 
stated. 

5.  No  children  under  six  years  were  included  in  the  tests. 
The  calculations  of  mental  age  were  made  by  the  writer  and  not 
in  any  case  by  the  students  engaged  in  making  the  tests. 

Practically  all  white  and  colored  children  in  the  Oberlin  Pub¬ 
lic  Schools  from  six  to  twelve  years  of  mental  age  were  tested. 
The  numbers  actually  recorded  in  the  tables  below,  after  eliminat¬ 
ing  all  those  affected  by  the  rules  just  mentioned,  were  96  negroes 
and  267  whites,  the  total  number  tested  must  have  been  half  as 
many  again. 

In  the  following  tables  the  figures  represent  percentages  of  the 
number  of  individuals  involved,  rather  than  actual  numbers. 
This  is  done  so  that  the  difference  in  number  of  negroes  and 
whites  may  be  equalized.  But  for  purposes  of  simplification  one 
negro  is  counted  as  one  percent  of  the  total  number  of  negroes 
instead  of  1/96  of  one  percent,  which  is  the  strictly  accurate 
figure.  Likewise  in  the  case  of  the  whites  concerned  one  case 
counts  for  4/1 1  of  one  percent.  As  there  are  267  whites  con¬ 
cerned  the  absolutely  correct  figure  would  be  100/267  of  one  per 
cent,  a  rather  unwieldly  figure. 

Table  No.  1  shows  the  distribution  of  advancements  and  re¬ 
tardations  for  from  six  to  twelve  years  mental  age,  with  some 
cases  running  as  high  as  sixteen  years  of  actual  age.  The  table 


RETARDED 


TABLE  I 


ADVANCED  RETARDED 


TABLE  II 


6 

W 

X 

7 

W 

N 

8 

W 

N 

W 

) 

N 

10 

w 

N 

11 

W 

X.' 

12 

w 

N 

13 

W  N 

14 

W  X 

15 

W  X 

16 

W  X 

3  to  4  years 

Vu 

7j 

1 

2  to  3  years 

l7ii 

1 

i7« 

1% 

1 

1  to  2  years 

4/ 

/  11 

3 

44Ai 

2 

sV^ 

1 

67, 

1 

«7u 

1 

to  1  year 

4 

I 

4 

8 

»TAi 

11 

210/ 

11 

1 

47n 

6 

8 

7xx 

Normal 

«/ 

/  11 

1 

i7» 

1 

Vu 

7, 

1 

2 

iVxi 

2 

I7n 

l7xx 

to  1  year 

i7n 

4 

*T/ii 

5 

i7, 

1 

2 

»7tx 

4 

27.x 

2 

67  xi 

5 

8/ 

/  11 

1  to  2  years 

Vu 

7, 

1 

i 

*7u 

1 

l7xx 

2 

l7xx 

5 

4 

2 

l7xx 

2  to  3  years 

7xx 

7xx 

1 

22/ 

2 

87/ ii  5 

3  to  4  years 

7xx 

7xx 

1 

7xx  5 

8/ 

/ 11 

3 

4  to  5  years 

7xx 

7xx 

7xx 

V 
/ 11 

3 

8/ 

/ 11 

5  to  6  years 

1 

1 

TABLE  III 


6 

W  N 

7 

W  N 

5z; 

00 

£ 

1 

w‘ 

X 

10 

W  N 

11 

W  N 

12 

W  N 

13 

W  N 

14 

W  X 

15 

W  X 

16 

W  X 

Advanced 

47xi  4 

lO^/xx  11 

97:x  12 

11 V 

u  1 

6>7xx  7 

8 

7xi 

Normal 

7ix  i 

l7 11  1 

7xx 

7 

LX  2 

i7u  2 

I7xi 

l7xx 

Retarded 

l7xx  4 

4  5 

27 

x  3 

57xx  5 

47  xx  4 

8  11 

77/xx  5 

57xx  10 

I7xx  7 

8/  1 
/  11  1 

TABLE  IV 


6 

W  N 

7  8 

W  N  :  W  X 

9 

W 

10 

N  W  N 

11 

W  X 

12 

W  X 

13 

W  X 

14 

W  X 

15 

W  X 

16 

W  X 

Advancement 

Units 

Retardation 

Units 

13  7(19) 

58  15(41)  45  13(3(5) 

4  4(11)  12  5(14) 

60  1 

9  4 

(3)  25  8(22) 

(11)  26  6(16) 

22 

22  6(16) 

1 

29  18(49) 

51  14(38) 

45  35(96) 

13  33(91) 

10  6(16) 

APPLICATION  OF  THE  BINET-SIMON  TESTS 


55 


shows  advancements  and  retardations  in  terms  of  1/5  years,  after 
the  familiar  Binet-Simon  method. 

Table  No.  2  is  inserted  for  purposes  of  convenience  to  pro¬ 
vide  a  summary  of  Table  1.  The  figures  are  the  same  as  in  the 
first  table  except  that  they  are  for  years,  instead  of  for  fifths  of 
years. 

Table  No.  3  is  a  summary  of  the  total  percentages  retarded, 
advanced  and  normal  for  both  races.  Inasmuch  as  only  those 
were  counted  normal  who  were  exactly  at  the  age  level  to  the 
fifth  of  a  year,  the  number  seems  small.  The  reckoning  of  the 
actual  age  of  the  children  in  fifths  of  a  year  was  done  easily  and 
accurately  by  consulting  the  school  records  of  the  date  of  birth. 

A  view  of  the  final  results  is  given  in  Table  No.  4,  which  is 
so  arranged  that  at  a  glance  one  may  observe  the  relative  results 
from  the  two  races,  without  being  confused  by  the  fact  that  there 
were  about  two  and  a  half  times  as  many  whites  as  negroes  con¬ 
cerned  in  the  tests.  Also  the  total  amount  of  retardation  is  in¬ 
dicated,  as  well  as  the  number  retarded.  These  are  two  different 
things,  for  while  one  race  might  have  more  actual  cases  of  re¬ 
tardation  than  the  other,  in  the  case  of  the  second  race  the  de¬ 
gree  of  retardation  in  the  cases  of  those  who  were  backward 
might  be  comparatively  very  high.  Therefore  the  Table  is  an 
arrangement  of  what  may  be  called  “retardation  units.”  A  “re¬ 
tardation  unit”  may  be  considered  as  one  case  retarded  for  one 
year  or  for  part  of  one  year.  Thus  the  retardation  of  a  child  three 
years  behind  his  age  level  would  be  recorded  as  three  units.  “Ad¬ 
vancement  units”  are  reckoned  in  a  similar  way.  The  figures 
which  give  the  units  of  retardation  and  advancement  for  the 
negroes  are  followed  by  other  figures  in  brackets.  These  brack¬ 
eted  figures  are  the  numbers  of  units  earned  by  the  negroes  mul¬ 
tiplied  by  1 1/4.  The  figures  thus  obtained  are  directly  com¬ 
parable  with  the  number  of  units  earned  by  the  whites,  and  en¬ 
ables  the  reader  easily  to  compare  the  performances  of  the  two 
races. 

If  these  results  are  carefully  examined  it  will  be  seen  that  the 
whites  make,  in  the  whole,  a  little  the  better  showing.  The  great- 


56 


GEORGE  R.  WELLS 


est  advancement  reckoned  in  terms  of  averages  is  white,  and  the 
individuals  which  were  most  advanced  were  white.  On  the  other 
hand  the  greatest  retardation  in  point  of  averages,  and  the  most 
retarded  individuals  were  negroes.  The  arrangement  in  terms 
of  retardation  units  is  still  more  strongly  indicative  of  an  ad¬ 
vantage  on  the  part  of  the  whites.  The  total  number  of  retarda¬ 
tion  units  on  the  part  of  the  whites  is  221,  and  on  the  part  of  the 
negroes  is  358.  The  advancement  units  for  the  whites  number 
224,  and  for  the  blacks  12 1.  In  both  of  these  cases  the  figures 
given  for  the  negroes  is  that  obtained  by  the  equalization  pro¬ 
cess  of  multiplying  the  actual  number  of  negro  units  by  11/4. 
Judging  by  any  of  these  Tables  there  is  a  small  but  not  insignifi¬ 
cant  advantage  in  favor  of  the  whites. 

But  far  more  important  than  the  mere  fact  of  a  better  showing 
made  by  one  of  the  racial  groups  is  the  arrangement  of  the  re¬ 
sults  as  regards  ages.  It  is  very  noticeable  that  the  negroes  are  at 
least  equal  to  the  whites  at  the  ages  of  six,  seven,  and  eight.  Nor 
are  the  negroes  very  markedly  inferior  to  the  whites  at  the  ages 
of  nine,  ten  and  eleven.  At  twelve  years  there  is  a  marked  dif¬ 
ference,  and  it  becomes  progressively  more  marked  from  twelve 
to  sixteen,  reaching  its  climax  at  fourteen  and  fifteen.  Evidently 
the  children  start  in  on  equal  terms,  and  maintain  that  equality 
for  some  years.  But  gradually  the  negroes  lag  behind,  and  at 
about  the  age  of  finishing  grammar  school  or  entering  high  school 
seem  to  be  definitely  inferior  to  the  whites.  There  are,  of  course, 
many  exceptions.  These  results  are  to  be  understood  as  averages 
of  performances  of  a  moderately  large  number  of  school  children. 
Their  significance  must  not  be  mistaken  nor  exaggerated.  But 
it  seems  to  be  beyond  doubt  that  under  the  conditions  mentioned, 
and  using  the  tests  which  we  used  there  is  no  difference  in  the 
reactions  of  white  and  colored  children  up  to  the  age  of  ten  or 
eleven.  At  the  age  of  twelve  a  difference  is  noticeable,  which 
difference  becomes  very  prominent  at  fourteen,  fifteen  and  sixteen 
years  of  age.  That  the  negroes  are  outstripped  seems  undeniable. 

It  remains  to  determine  the  cause  of  this  difference.  The 
simplest  explanation  and  that  which  comes  first  to  one  is  that 


APPLICATION  OF  THE  BINE T-SIM ON  TESTS 


57 


it  is  a  manifestation  of  some  inherent  mental  superiority  of  the 
white  race  over  the  negro.  But  it  seems  evident  to  the  writer 
that  such  an  explanation  can  not  be  applied  in  this  specific  case. 
One  reason  will  sufficiently  dispose  of  it,  and  that  is  the  impossi¬ 
bility  of  determining  the  purity  of  blood  of  many  negroes.  Be¬ 
yond  all  doubt  most,  if  not  all,  of  the  colored  children  examined 
have  some  mixture  of  white  blood,  in  proportions  impossible  to 
determine. 

The  correct  explanation  will  probably  be  found  when  the 
social  conditions  and  limitations  of  the  two  races  are  examined. 
Mr.  Howard  L.  Rawdon,  the  Superintendent  of  the  Oberlin 
School  System,  has  gone  into  the  question  of  the  social  differences 
confronting  the  two  races  in  a  report  presented  to  the  Department 
of  Education  of  Oberlin  College  and  entitled  “The  Colored 
Pupil  in  the  Oberlin  Public  Schools.”  He  points  out  that  the 
limitation  of  possible  professions  for  negroes  is  so  great  that 
there  is  smaller  incentive  to  continue  at  school  than  operates  in 
the  case  of  the  white  children.  He  also  shows  that  the  economic 
position  of  the  negroes  in  Oberlin  is  not  good.  The  colored  peo¬ 
ple  constituted  something  more  than  18%  of  the  population  of 
Oberlin  in  1913,  but  owned  no  more  than  4%  of  the  taxable 
property.  And  what  is  still  more  significant  is  the  fact  that  less 
than  7/10  of  one  percent  of  the  personal  property  is  owned  by 
negroes.  The  percapita  wealth  of  the  whites  is  more  than  five 
times  that  of  the  colored  people.  Further,  records  of  crime  in 
Oberlin  show  that  the  colored  people  are  responsible  for  far  more 
than  their  share,  calculated  on  their  proportion  of  population. 
And  this  criminal  tendency  becomes  even  more  marked  if  serious 
crimes  only  be  considered,  and  mere  violations  of  local  ordinances 
be  neglected. 

The  social  and  moral  conditions  so  briefly  mentioned  above 
may  properly  be  held  responsible  for  the  very  great  irregularity 
of  school  attendance  and  for  the  large  amount  of  tardiness  in 
the  case  of  negro  children  in  general.  Mr.  Rawdon  states  that 
the  school  records  show  that  the  colored  pupils  are  absent  prac¬ 
tically  fifty  percent  more  than  the  white  pupils,  and  that  the  boys 


58 


GEORGE  R.  WELLS 


are  absent  oftener  than  the  girls,  the  reverse  of  the  case  with  the 
whites.  It  is  also  very  significant  that  the  colored  pupils  drop 
out  of  school  much  earlier  than  do  the  whites.  For  instance,  in 
the  four  lower  grades  27.4  %  of  the  enrollment  is  colored;  in  the 
four  upper  grades,  21.8%  and  in  the  High  School  but  10.3  % 
are  colored.  No  doubt  much  of  this  absence  and  early  leaving  of 
school  is  due  to  economic  pressure  driving  the  children  to  work, 
much  of  it  is  also  due  to  the  generally  unpromising  outlook  for 
the  colored  student,  even  if  he  does  graduate  from  High  School. 
And  to  this  latter  cause  and  the  unambitious  attitude  it  en¬ 
genders  is  due  the  excessive  amount  of  tardiness,  which  Mr. 
Rawdon  also  notes. 

The  writer  feels  that  the  probability  is  that  the  disparity  in 
performance  between  the  groups  of  white  and  colored  children 
which  he  and  his  assistants  tested  is  due  to  social  and  environ¬ 
mental  factors  rather  than  to  inherited  or  racial  traits  of  mental 
ability. 


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